BIOLOGY 

i  2BRASY 
G 


f. 


-3  HH 


FRONTISPIECE. — A  Shade  Plant,  Jack-in-tke-Pulpii 


FOUNDATIONS  OF  BOTANY 


BY 


JOSEPH  Y.  BERGEN,  A.M. 
V 

INSTRUCTOR  IN  BIOLOGY,  ENGLISH  HIGH  SCHOOL,  BOSTON 


BOSTON,  U.S.A. 

GINN   &   COMPANY,  PUBLISHERS 
&tbensettm 
1901 


r      \. 


BIOLOGY 

LIBRARY 

G 


COPYBIGHT,  1901,  BY 
JOSEPH    Y.   BERGEN 


ALL  RIGHTS  RESERVED 


PREFACE 

THIS  book  is  written  upon  the  same  plan  as  the  author's 
Elements  of  Botany.  A  few  chapters  stand  here  but  little 
altered  from  the  former  work,  but  most  of  them  have  been 
rewritten  and  considerably  enlarged,  and  many  new  ones 
have  been  added.  The  principal  changes  in  the  book  as  a 
whole  are  these  : 

1.  Most  of  the  discussion  of  ecological  topics  is  put  by 
itself,  in  Part  II. 

2.  The  amount  of  laboratory  work  on  the  anatomy  and 
physiology  of  seed-plants  is  considerably  increased  and  addi- 
tional experiments  are  introduced. 

3.  The  treatment  of  spore-plants  is  greatly  extended,  so  as 
to  include  laboratory  work  on  the  most  important  groups. 

4.  The  meagre  Flora  which  accompanied  the  earlier  book 
has  been  replaced  by  one  which  contains  fairly  full  descrip- 
tions of  nearly  seven  hundred  species  of  plants.      Most  of 
these  are  wild,  but  a  considerable  number  of  cultivated  species 
have  been  included,  mainly  for  the  convenience  of  schools  in 
large  cities. 

Ample  material  is  offered  for  a  year's  course,  four  or  five 
periods  per  week.  The  author  is  well  aware  that  most  schools 
devote  but  half  a  year  to  botany,  but  the  tendency  sets  strongly 
toward  allowing  more  time  for  this  subject.  Even  in  schools 
where  the  minimum  time  allowance  is  devoted  to  botany,  there 
is  a  distinct  advantage  in  being  provided  with  a  book  which 
allows  the  teacher  considerable  option  as  regards  the  kind 
and  amount  of  work  which  he  shall  offer  to  his  classes. 


iv  PREFACE 

Suggestions  are  made  in  the  teacher's  Handbook,  which 
accompanies  this  volume,  in  regard  to  shaping  half-year 
courses. 

The  latest  authorities  in  the  various  departments  of  botany 
have  been  consulted  on  all  doubtful  points,  and  the  attempt 
has  been  to  make  the  book  scientifically  accurate  throughout, 
yet  not  unduly  difficult. 

Most  of  the  illustrations  have  been  redrawn  from  those  in 
standard  German  works  of  an  advanced  character,  or  drawn 
from  nature  or  from  photographs,  expressly  for  this  book. 
Besides  the  sources  of  drawings  acknowledged  in  the  author's 
Elements,  many  cuts  have  been  taken  from  the  botanies  of 
Frank,  Prantl,  Detmer,  Murray,  and  Bennett  and  Murray,  as 
well  as  from  Schimper's  Pflanzengeographie. 

Of  the  drawings  from  nature  or  from  photographs,  some 
figures,  and  Plates  I,  VII,  and  VIII,  are  by  Mr.  Edmund 
Garrett  of  Boston  ;  several  figures,  the  Frontispiece,  and 
Plates  II,  IV,  X,  XI,  are  by  Mr.  Bruce  Horsfall  of  New  York  ; 
several  figures  are  by  Mr.  F.  Schuyler  Mathews  of  Boston  ;  a 
large  number  of  figures  and  Plate  V  are  by  Mr.  E.  N.  Fischer 
of  Boston;  several  figures  are  by  Mr.  E.  B,.  Kingsbury  of  Boston 
and  Dr.  J.  W.  Folsom  of  the  University  of  Illinois. 

Thanks  for  the  use  of  photographs  are  due  to  Mr.  H.  G. 
Peabody  of  Boston  (Fig.  234),  to  Mr.  J.  H.  White  of  Boston 
(Figs.  32,  75,  222),  to  Professor  Conway  MacMillan  of  the  Uni- 
versity of  Minnesota  (Frontispiece),  and  to  Professor  F.  V. 
Coville  of  Washington  (Plate  VII).  Figs.  28  and  275  are 
taken  by  permission  from  the  Primer  of  Forestry,  issued  by  the 
Division  of  Forestry,  U.  S.  Department  of  Agriculture.  Figs. 
263,  264,  276  are  copied  by  permission  from  Professor  W.  J. 
Beal's  Seed  Dispersal,  and  Figs.  226,  229,  233  from  Professor 
W.  M.  Davis's  Physical  Geography.  Fig.  269  is  from  a  photo- 
graph by  Professor  C.  F.  Millspaugh  of  the  Field  Columbian 
Museum,  Chicago. 


PREFACE  V 

Most  of  the  redrawn  illustrations  (not  microscopical)  from 
various  European  sources  are  by  Mr.  Fischer.  Most  of  the 
microscopical  ones  (and  a  number  of  figures  from  nature)  are 
by  Dr.  J.  W.  Folsom  of  the  University  of  Illinois,  and  many 
of  both  classes  are  by  Mr.  Mathews.  Thanks  are  due  to 
Professor  J.  M.  Holzinger  of  the  Winona  (Minn.)  State 
Normal  School,  to  Professor  L.  Murbach  of  the  Detroit  High 
School,  and  to  Mr.  I.  S.  Cutter  of  Lincoln,  Nebraska,  for 
their  many  discriminating  criticisms  of  the  proof  of  Parts  I 
and  II.  Mr.  Samuel  F.  Tower  of  the  Boston  English  High 
School,  Professor  Charles  V.  Piper  of  the  Washington  State 
Agricultural  College,  and  Dr.  Rodney  H.  True,  Lecturer  on 
Botany  at  Harvard  University,  have  all  read  the  whole  or 
large  portions  of  Part  I  and  given  valuable  suggestions. 
Professor  W.  F.  Ganong,  of  Smith  College,  has  read  and 
criticised  Part  II. 

The  chapters  on  spore-plants,  excepting  a  small  amount  of 
matter  retained  from  the  Elements  of  Botany,  are  entirely  the 
work  of  Mr.  A.  B.  Seymour  of  the  Cryptogamic  Herbarium  of 
Harvard  University. 

The  author  has  attempted  to  steer  a  middle  course  between 
the  advocates  of  the  out-of-door  school  and  of  the  histological 
school  of  botany  teaching.  He  has  endeavored  never  to  use  a 
technical  term  where  he  could  dispense  with  it,  and  on  the 
other  hand,  not  to  become  inexact  by  shunning  necessary 
terms.  In  deciding  questions  of  this  sort,  a  priori  reasoning 
is  of  little  value  ;  one  must  ascertain  by  repeated  trials  how 
much  of  a  technical  vocabulary  the  average  beginner  in  botany 
can  profitably  master.  The  teacher  who  has  discovered  that 
not  one  of  the  boys  in  a  division  of  thirty-six  pupils  knows 
that  his  own  desk-top  is  of  cherry  wood  may  well  hesitate 
about  beginning  his  botany  teaching  with  a  discourse  on  cen- 
trospheres  and  karyokinesis.  It  has  been  assumed  throughout 
this  book  that,  other  things  being  equal,  the  knowledge  is  of 


VI  PREFACE 

most  worth,  which  touches  the  pupil's  daily  life  at  the  most 
points,  and  therefore  best  enables  him  to  understand  his  own 
environment.  On  the  other  hand,  the  author  has  no  sympathy 
with  those  who  decry  the  use  of  apparatus  in  botany  teaching 
in  secondary  schools  and  who  would  confine  the  work  of  their 
pupils  mainly  within  the  limits  of  what  can  be  seen  with  the 
unaided  eye.  If  the  compound  microscope  plainly  reveals 
things  shown  only  imperfectly  by  a  magnifier  and  not  seen  at 
all  with  the  naked  eye,  —  use  the  microscope  !  If  iodine 
solution  or  other  easily  prepared  reagents  make  evident  the 
existence  of  structures  or  substances  not  to  be  detected  with- 
out them,  —  then  use  the  reagents  !  No  one  thinks  of  deny- 
ing a  boy  the  use  of  a  spyglass  or  a  compass  for  his  tramps 
afield  or  his  outings  in  a  boat  because  he  has  not  studied 
physics.  No  one  would  refuse  to  let  an  intelligent  boy  or 
girl  use  a  camera  because  the  would-be  photographer  had  not 
mastered  the  chemical  reactions  that  follow  upon  the  expo- 
sure of  a  sensitized  plate.  Yet  it  is  equally  illogical  to  defer 
some  of  the  most  fascinating  portions  of  botanical  study  until 
the  college  course,  to  which,  most  never  attain.  When  the 
university  professor  tells  the  teacher  that  he  ought  not  to 
employ  the  ordinary  appliances  of  elementary  biological  inves- 
tigation in  the  school  laboratory  because  the  pupils  cannot 
intelligently  use  them,  the  teacher  is  forced  to  reply  that  the 
professor  himself  cannot  intelligently  discuss  a  subject  of 
which  he  has  no  personal  knowledge.  The  pupils  are  deeply 
interested;  they  prove  by  their  drawings  and  their  recita- 
tions that  they  have  seen  a  good  way  into  plant  structures 
and  plant  functions  ; .  then  why  not  let  them  study  botany 
in  earnest  ? 

J.  Y.  B. 
CAMBRIDGE,  January,  1901. 


CONTENTS 

.- 

PART  I 

STRUCTURE,  FUNCTIONS,  AND  CLASSIFICATION  OF  PLANTS 

CHAPTER  I 
THE  SEED  AND  ITS  GERMINATION       ......         5-13 

CHAPTER  II 
STORAGE  OF  FOOD  IN  THE  SEED         ......       14-24 

CHAPTER  III 
MOVEMENTS,  DEVELOPMENT,  AND  MORPHOLOGY  OF  THE  SEEDLING       25-35 

CHAPTER  IV 
ROOTS          . 36-61 

CHAPTER  V 
STEMS .  •     62-82 

CHAPTER  VI 
STRUCTURE  OF  THE  STEM    ........     83-103 

CHAPTER  VII 
LIVING  PARTS  OF  THE  STEM  ,    WORK  OF  THE  STEM  .         .         ,  104-118 

CHAPTER  VIII 

BUDS 119-129 

vii 


Vlll  CONTENTS 

CHAPTER  IX  PAGES 

LEAVES 130-139 

CHAPTER  X 

LEAF-ARRANGEMENT  FOR  EXPOSURE  TO  SUN  AND  AIR  ;    MOVE- 
MENTS OF  LEAVES  AND  SHOOTS    ......   140-149 

CHAPTER  XI 
MINUTE  STRUCTURE  OF  LEAVES  ;   FUNCTIONS  OF  LEAVES  .         .   150-177 

CHAPTER  XII 
PROTOPLASM  AND  ITS  PROPERTIES       ......  178-185 

CHAPTER  XIII 
INFLORESCENCE,  OR  ARRANGEMENT  OF  FLOWERS  ON  THE  STEM  186-191 

CHAPTER  XIV 
THE  STUDY  OF  TYPICAL  FLOWERS 192-196 

CHAPTER  XV 
PLAN  AND  STRUCTURE  OF  THE  FLOWER  AND  ITS  ORGANS  .  197-207 

CHAPTER  XVI 

TRUE  NATURE  OF  FLORAL  ORGANS  ;  DETAILS  OF  THEIR  STRUC- 
TURE ;  FERTILIZATION  ........  208-216 

CHAPTER  XVII 
THE  STUDY  OF  TYPICAL  FRUITS          ......  217-220 

CHAPTER  XVIII 
THE  FRUIT 221-227 

CHAPTER  XIX 

THE  CLASSIFICATION  OF  PLANTS         .,,..•  228-234 


CONTENTS 


IX 


CHAPTER  XX 
TYPES  OF  CRYPTOGAMS  ;   THALLOPHYTES    . 

'CHAPTER  XXI 
TYPES  OF  CRYPTOGAMS;   BRYOPHYTES 

CHAPTER  XXII 
TYPES  OF  CRYPTOGAMS;   PTERIDOPHYTES  . 

CHAPTER  XXIII 
THE  EVOLUTIONARY  HISTORY  OF  PLANTS  . 


PAGES 
.  235-276 


.  277-285 


.  286-297 


.  298-305 


PART  II 

ECOLOGY,  OB  RELATIONS  OP  PLANTS  TO  THE  WORLD 
ABOUT  THEM 


CHAPTER  XXIV 
PLANT  SOCIETIES 307-323 

CHAPTER  XXV 
BOTANICAL  GEOGRAPHY       .         .         .         .         .         .         .         .  324-335 

CHAPTER  XXVI 
PARASITES,  ENSLAVED  PLANTS,  MESSMATES,  CARNIVOROUS  PLANTS  336-344 

CHAPTER  XXVII 
How  PLANTS  PROTECT  THEMSELVES  FROM  ANIMALS  .         .  345-352 


CONTENTS 


CHAPTER  XXVIII 

PAGKS 

ECOLOGY  OF  FLOWERS         ...  .  353-372 


CHAPTER  XXIX 
How  PLANTS  ARE  SCATTERED  AND  PROPAGATED        .         .         .  373-386 

CHAPTER  XXX 

THE    STRUGGLE    FOR   EXISTENCE    AND   THE   SURVIVAL   OF   THE 

FITTEST         .  387-395 


LIST    OF   PLATES 

FRONTISPIECE.  Jack-in-the-pulpit,  a  typical  shade-plant,  with  large, 
thin  leaves. 

Facing  page 

PLATE  I.  Sand-dunes  with  sea  rye  grass.  Deep-rooted,  with  exten- 
sively running  rootstocks  . 76 

PLATE  II.     Pollarded  willows,  showing  growth  of  slender  twigs  from 

adventitious  buds        .         .         ....        .        .         .         .  128 

PLATE  III.  Japanese  ivy,  a  tendril-climber  growing  on  face  of  a 
building,  showing  leaves  all  exposed  to  sunlight  at  the  most 
advantageous  angle .  .  140 

PLATE  IV.  Cypress  swamp,  showing  "  Spanish  moss "  (Tillandsia)? 
a  phanerogamic  epiphyte  practically  leafless,  the  work  ordinarily 
done  by  leaves  devolving  on  the  slender  stems.  The  cypress 
trees  are  furnished  with  "  knees  "  or  projections  from  the  roots, 
which  are  thought  by  some  to  absorb  air  .  .  .  .  .158 

PLATE  V.     Indian  pipe,  a  saprophytic  seed-plant,  wholly  destitute 

of  chlorophyll  and  with  scales  instead  of  foliage  leaves        .         .   168 

PLATE  VI.  Fan  palms,  showing  general  habit  of  the  tree,  and  large 
projecting  bases  of  old  petioles  left  after  the  decay  of  the  leaves  176 

PLATE  VII.     A  tree  yucca  in  the  Mohave  Desert,  a  characteristic 

xerophytic  tree.     Other  sparse  desert  vegetation  is  also  shown  .  316 

PLATE  VIII.  Belt  of  trees  along  a  Nebraskan  river,  showing  depend- 
ence of  forest  on  water  supply 334 

PLATE  IX.  Cottonwood.  Tree  largely  overgrown  with  American 
mistletoe,  near  Mesilla,  New  Mexico.  The  photograph  was  taken 
in  whiter,  when  the  tree  was  leafless,  so  that  all  the  foliage  shown 
is  that  of  the  mistletoe 336 

PLATE  X.  Humming-bird  visiting  flowers  of  the  trumpet  creeper. 
This  is  one  of  the  best  North  American  examples  of  a  flower 
mainly  pollinated  by  birds 362 

PLATE  XI.  Asters  and  golden-rods,  Compositse,  illustrating  the 
principle  of  grouping  many  small  flowers  into  heads  (and  in 
the  golden-rod  the  heads  into  rather  close  clusters)  to  facilitate 
the  visits  of  insects  .  .  372 


FOUNDATIONS  OF  BOTANY 


INTRODUCTION 

"  Botany  is  the  science  which  endeavors  to  answer  every  reason- 
able question  about  plants."  l 

THE  plant  is  a  living  being,  provided  generally  with 
many  parts,  called  organs-,  which  it  uses  for  taking  in  nour- 
ishment, for  breathing,  for  protection  against  its  enemies, 
and  for  reproducing  itself  and  so  keeping  up  the  numbers 
of  its  own  kind.  The  study  of  the  individual  plant  there- 
fore embraces  a  variety  of  topics,  and  the  examination  of 
its  relation  to  others  introduces  many  more  subjects. 

Morphology,  or  the  science  of  form,  structure,  and  so  on, 
deals  with  the  plant  without  much  regard  to  its  character 
as  a  living  thing.  Under  this  head  are  studied  the  forms 
of  plants  and  the  various  shapes  or  disguises  which  the 
same  sort  of  organ  may  take  in  different  kinds  of  plants, 
their  gross  structure,  their  microscopical  structure,  their 
classification,  and  the  successive  stages  in  the  develop- 
ment of  the  individual  plant. 

Plant  Physiology  treats  of  the  plant  in  action,  how  it  lives, 
breathes,  feeds,  grows,  and  produces  others  like  itself. 

Geographical  Distribution,  or  botanical  geography,  dis- 
cusses the  range  of  the  various  kinds  of  plants  over  the 

1  Professor  George  L.  Goodale. 

1 


2  FOUNDATION'S   OF   BOTANY 

earth's  surfaced  Another  subdivision  of  botany,  usually 
studied  along  witfe  geology,  describes  the  history  of  plant 
life  on  the  earth  from  the  appearance  of  the  first  plants 
until  the  present  time. 

L  Systematic  Botany,  or  the  classification  of  plants,  should 
naturally  follow  the  examination  of  the  groups  of  seed- 
plants  and  spore-plants. 

Plant  Ecology  treats  of  the  relations  of  the  plant  to 
the  conditions  under  which  it  lives.  Under  this  division 
of  the  science  are  studied  the  effects  of  soil,  climate,  and 
friendly  or  hostile  animals  and  plants  on  the  external 
form,  the  internal  structure,  and  the  habits  of  plants. 
This  is  in  many  respects  the  most  interesting  department 
of  botany,  but  it  has  to  be  studied  for  the  most  part  out 
of  doors. 

Many  of  the  topics  suggested  in  the  above  outline  cannot 
well  be  studied  in  the  high  school.  There  is  not  usually 
time  to  take  up  more  than  the  merest  outline  of  botanical 
geography,  or  to  do  much  more  than  mention  the  impor- 
*-"  tant  subject  of  Economic  Botany  —  the  study  of  the  uses 
of  plants  to  man.  It  ought,  however,  to  be  possible  for 
the  student  to  learn  in  his  high-school  course  a  good  deal 
about  the  simpler  facts  of  morphology  and  of  vegetable 
physiology.  One  does  not  become  a  botanist  —  not  even 
much  of  an  amateur  in  the  subject  —  by  reading  books 
about  botany.  It  is  necessary  to  study  plants  themselves, 
to  take  them  to  pieces  and  make  out  the  connection  of  their 
parts,  to  examine  with  the  microscope  small  portions  of  the 
exterior  surface  and  thin  slices  of  all  the  variously  built 
materials  or  tissues  of  which  the  plant  consists.  All  this 
can  be  done  with  living  specimens  or  with  those  taken 


INTRODUCTION  6 

from  dead  parts  of  plants  that  have  been  preserved  in  any 
suitable  way,  as  by  drying  or  by  placing  in  alcohol  or  other 
fluids  which  prevent  decay.  Living  plants  must  be  studied 
in  order  to  ascertain  what  kinds  of  food  they  take,  what 
kinds  of  waste  substances  they  excrete,  how  and  where 
their  growth  takes  place  and  what  circumstances  favor  it, 
how  they  move,  and  indeed  to  get  as  complete  an  idea  as 
possible  of  what  has  been  called  the  behavior  of  plants. 

Since  the  most  familiar  and  most  interesting  plants 
spring  from  seeds,  the  beginner  in  botany  can  hardly  do 
better  than  to  examine  at  the  outset  the  structure  of  a  few 
familiar  seeds,  then  sprout  them  and  watch  the  growth  of 
the  seedlings  which  spring  from  them.  Afterwards  he 
may  study  in  a  few  typical  examples  the  organs,  structure, 
and  functions  of  seed-plants,  trace  their  life  history,  and 
so,  step  by  step,  follow  the  process  by  which  a  new  crop 
of  seeds  at  last  results  from  the  growth  and  development 
of  such  a  seed  as  that  with  which  he  began. 

After  he  has  come  to  know  in  a  general  way  about  the 
structure  and  functions  of  seed-plants,  the  student  may 
become  acquainted  with  some  typical  cryptogams  or  spore- 
plants.  There  are  so  many  groups  of  these  that  only  a 
few  representative  ones  can  be  chosen  for  study. 


* 


PART  I 

STRUCTURE,    FUNCTIONS,   AND    CLASSIFI- 
CATION  OF   PLANTS 

CHAPTER   I 

THE    SEED   AND   ITS    GERMINATION 

1.  Germination  of  the  Squash  Seed.  —  Soak  some  squash  seeds  in 
tepid  water  for  twelve  hours  or  more.  Plant  these  about  an  inch 
deep  in  damp  sand  or  pine  sawdust  or  peat-moss  in  a  wooden  box 
which  has  had  holes  enough  bored  through  the  bottom  so  that  it  will 
not  hold  water.  Put  the  box  in  a  warm  place  (not  at  any  time  over 
70°  or  80°  Fahrenheit),1  and  cover  it  loosely  with  a  board  or  a  pane 
of  glass.  Keep  the  sand  or  sawdust  moist,  but  not  wet,  and  the 
seeds  will  germinate.  As  soon  as  any  of  the  seeds,  on  being  dug  up, 
are  found  to  have  burst  open,  sketch  one  in  this  condition,2  noting 
the  manner  in  which  the  outer  seed-coat  is  split,  and  continue  to 
examine  the  seedlings  at  intervals  of  two  days,  until  at  least  eight 
stages  in  the  growth  of  the  plantlet  have  been  noted.3 

1  Here  and  elsewhere  throughout  the  book  temperatures  are  expressed  in 
Fahrenheit  degrees,  since  with  us,  unfortunately,  the  Centigrade  scale  is  not 
the  familiar  one,  outside  of  physical  and  chemical  laboratories. 

2  The  student  need  not  feel  that  he  is  expected  to  make  finished  drawings 
to  record  what  he  sees,  but  some  kind  of  careful  sketch,  if  only  the  merest 
outline,  is  indispensable.     Practice  and  study  of  the  illustrations  hereafter 
given  will  soon  impart  some  facility  even  to  those  who  have  had  little  or  no 
instruction  in  drawing.     Consult  here  Figs.  9  and  89. 

3  The  class  is  not  to  wait  for  the  completion  of  this  work  (which  may,  if 
desirable,  be  done  by  each  pupil  at  home),  but  is  to  proceed  at  once  with  the 
examination  of  the  squash  seed  and  of  other  seeds,  as  directed  in  the  follow- 
ing sections,  and  to  set  some  beans,  peas,  and  corn  to  sprouting,  so  that  they 
may  be  studied  at  the  same  time  with  the  germinating  squashes. 

5 


FOUNDATIONS   OF   BOTANY 


—  t 


\—-e 


Observe'  particularly  how  the  sand  is  pushed  aside  by  the  rise  of 
the  young  seedlings.     Suggest  some  reason  for  the  manner  in  which 
the  sand  is  penetrated  by  the  rising  stem. 

2,  Examination  of  the  Squash  Seed.  — 
Make  a  sketch  of  the  dry  seed,  natural  size. 
Note  the  little  scar  at  the  pointed  end  of  the 
seed  where  the  latter  was  attached  to  its 
place  of  growth  in  the  squash.  Label  this 
hilum. 

Note  the  little  hole  in  the  hilum ;  it  is 
the  micropyle,  seen  most  plainly  in  a  soaked 
seed.  (If  there  are  two  depressions  on  the 
hilum  the  deeper  one  is  the  micropyle.) 

Describe  the  color  and  texture  of  the  outer 
coating  of  the  seed.  With  a  scalpel  or  a  very 
sharp  knife  cut  across  near  the  middle  a  seed 
that  has  been  soaked  in  water  for  twenty- 
four  hours.  Squeeze  one  of  the  portions, 
held  edgewise  between  the  thumb  and  finger, 
in  such  a  way  as  to  separate  slightly  the 
halves  into  which  the  contents  of  the  seed  is 
naturally  divided.  Examine  with  the  mag- 
nifying glass  the  section  thus  treated,  make 
a  sketch  of  it,  and  label  the  shell  or  covering 
of  the  seed  and  the  kernel  within  this. 

Taking  another  soaked  seed,  chip  away 
the  white  outer  shell,  called  the  testa,  and 
observe  the  thin,  greenish  inner  skin  (Fig. 
1,  e),  with  which  the  kernel  of  the  seed  is 
closely  covered.1 

Strip  this  off  and  sketch  the  uncovered  ker- 
nel or  embryo.    Note  that  at  one  end  it  tapers 
to  a  point.     This  pointed  portion,  known 
as  the  hypocotyl,  will  develop  after  the  seed 
sprouts  into  the  stern  of  the  plantlet,  like  that  shown  at  c  in  Fig.  2. 
Split  the  halves  of   the  kernel  entirely  apart  from  each  other, 


cot. 


— c 


FIG.  1.— Lengthwise  Section 
of  a  Squash  Seed.  (Magni- 
fied about  five  times.) 


See  footnote  2  to  Sect.  18. 


THE    SEED   AND   ITS   GERMINATION 


noticing  that  they  are  only  attached  for  a  very  little  way  next  to 
the  hypocotyl,  and  observe  the  thickness  of  the  halves  and  the  slight 
unevenness  of  the  inner  surfaces.  These  halves  are  called  seed-leaves 
or  cotyledons. 

Have  ready  some  seeds  which  have  been  soaked  for  twenty-four 
hours  and  then  left  in  a  loosely  covered  jar  on  damp  blotting  paper 
at  a  temperature  of  70°  or  over 
until  they  have  begun. to  sprout. 

Split  one  of  these  seeds  apart, 
separating  the  cotyledons,  and 
observe,  at  the  junction  of  these, 
two  very  slender  pointed  objects, 
the  rudimentary  leaves  of  the 
plumule  or  first  bud  (Fig.  1,  p). 

3.  Examination  of  the  Bean. 
—  Study  the  seed,  both  dry  and 
after  twelve  hours'  soaking,  in 
the  same  general  way  in  which 
the  squash  seed  has  just  been 
examined.1 

Notice  the  presence  of  a  dis- 
tinct plumule,  consisting  of  a  pair 
of  rudimentary  leaves  between 
the  cotyledons,  just  where  they 

are  joined  to  the"  top  of  the  hypo-  FlG  2.  —  The  Castor  Bean  and  its 

Germination. 


cotyl.  In  many  seeds  (as  the  pea) 
the  plumule  does  not  show  dis- 
tinct leaves.  But  in  all  cases 
the  plumule  contains  the  growing 
point,  the  tip  of  the  stem  from 
which  all  the  upward  growth  of 
the  plant  is  to  proceed. 

Make  a  sketch  of  these  leaves  as  they  lie  in  place  on  one  of  the 
cotyledons,  after  the  bean  has  been  split  open. 

1  The  larger  the  variety  of  bean  chosen,  the  easier  it  will  be  to  see  and 
sketch  the  several  parts.  The  large  red  kidney  bean,  the  horticultural  bean, 
or  the  lima  bean  will  do  well  for  this  examination. 


A,  longitudinal  section  of  ripe  seed  ;  t, 
testa  ;  co,  cotyledon  ;  c,  hypocotyl ; 
B,  sprouting  seed  covered  with  endo- 
sperm ;  C,  same,  with  half  of  endo- 
sperm removed  ;  D,  seedling  ;  r,  pri- 
mary root ;  r',  secondary  roots ;  c,  arch 
of  hypocotyl. 


8  FOUNDATIONS   OF   BOTANY 

Note  the  cavity  in  each  cotyledon  caused  by  the  pressure  of  the 
plumule  and  of  the  hypocotyl. 

4.^  Examination  of  the  Pea.  — There  are  no  very  important  points 
of  difference  between  the  bean  and  pea,  so  far  as  the  structure  of 
the  seed  is  concerned,  but  the  student  should  rapidly  dissect  a  few- 
soaked  peas  to  get  an  idea  of  the  appearance  of  the  parts,  since  he 
is  to  study  the  germination  of  peas  in  some  detail. 

Make  only  one  sketch,  that  of  the  hypocotyl  as  seen  in  position 
after  the  removal  of  the  seed-coats.1 

5.  Germination  of  the  Bean  or  the  White  Lupine,  the  Pea,  and  the 
Grain  of  Corn.  —  Soak  some   beans   or   lupine   seeds  as  directed  in 
Section  3,  plant  them,2  and  make  a  series  of  sketches  on  the  same 
general  plan  as  those  in  Fig.  9. 

Follow  the  same  directions  with  some  peas  and  some  corn.  In  the 
case  of  the  corn,  make  six  or  more  sketches  at  various  stages  to  illus- 
trate the  growth  of  the  plumule  and  the  formation  of  roots ;  first  a 
main  root  from  the  base  of  the  hypocotyl,  then  others  more  slender 
from  the  same  region,  and  later  on  still  others  from  points  higher 
up  on  the  stem  (see  Fig.  15).  The  student  may  be  able  to  dis- 
cover what  becomes  of  the  large  outer  part  of  the  embryo.  This  is 
really  the  single  cotyledon  of  the  corn  (Fig.  6).  It  does  not  as  a 
whole  rise  above  ground,  but  most  of  it  remains  in  the  buried  grain, 
and  acts  as  a  digesting  and  absorbing  organ  through  which  the 
endosperm,  or  food  stored  outside  of  the  embryo  is  transferred  into 
the  growing  plant,  as  fast  as  it  can  be  made  liquid  for  that  purpose. 

6.  Germination  of  the  Horse-Chestnut .  —  Plant  some  seeds  of  the 
horse-chestnut  or  the  buckeye,  study  their  mode  of  germination,  and 
observe  the  nature  and  peculiar  modifications  of  the  parts. 

Consult  Gray's  Structural  Botany,  Vol.  I,  pp.  19,  20. 

/     7.    Conditions   Requisite  for   Germination.  —  When    we 
try  to  enumerate  the  external  conditions  which  can  affect 

1  The  teacher  will  find  excellent  sketches  of  most  of  the  germinating  seeds 
described  in  the  present  chapter  in  Miss  Newell's  Outlines  of  Lessons  in 
Botany,  Part  I. 

2  The  pupil  may  economize  space  by  planting  the  new  seeds  in  boxes 
from  which  part  of  the  earlier  planted  seeds  have  been  dug  up  for  use  in 
sketching,  etc. 


THE    SEED   AND   ITS   GERMINATION  9 

germination,  we  find  that  the  principal  ones  are  heat, 
moisture,  and  presence  of  air.  A  few  simple  experiments 
will  show  \vhat  influence  these  conditions  exert. 

8.  Temperature.  —  Common  observation  shows  that  a 
moderate  amount  of  warmth  is  necessary  for  the  sprout- 
ing of  seeds.  Every  farmer  or  gardener  knows  that 
during  a  cold  spring  many  seeds,  if  planted,  will  rot  in 
the  ground.  But  a  somewhat  exact  experiment  is  neces- 
sary to  show  what  is  the  best  temperature  for  seeds  to 
grow  in,  and  whether  variations  in  the  temperature  make 
more  difference  in  the  quickness  with  which  they  begin 
to  germinate  or  in  the  total  per  cent  which  finally  succeed. 

EXPERIMENT   I 

Relation  of  Temperature  to  Germination.  —  Prepare  at  least  four 
teacups  or  tumblers,  each  with  wet  soft  paper  packed  in  the  bottom 
to  a  depth  of  nearly  an  inch.  Have  a  tightly  fitting  cover  over  each. 
Put  in  each  vessel  the  same  number  of  soaked  peas.  Stand  the  ves- 
sels with  their  contents  in  places  where  they  will  be  exposed  to  dif- 
ferent, but  fairly  constant,  temperatures,  and  observe  the  several 
temperatures  carefully  with  a  thermometer.  Take  pains  to. keep  the 
tumblers  in  the  warm  places  from  drying  out,  so  that  their  contents 
will  not  be  less  moist  than  that  of  the  others.  The  following  series 
is  merely  suggested,  —  other  values  may  be  found  more  convenient. 
Note  the  rate  of  germination  in  each  place  and  record  in  tabular 
form  as  follows : 

No.  of  seeds  sprouted  in   24  hrs.    48  hrs.    72  hrs.    96  hrs.    etc. 
At  32°, 
At  50°, 
At  70°, 
At  900,1 


1  For  the  exact  regulation  of  the  temperatures  a  thermostat  (see  Handbook) 
is  desirable.  If  one  is  available,  a  maximum  temperature  of  100°  or  over 
should  be  tried. 


10 


FOUNDATIONS   OF   BOTANY 


9,  Moisture.  —  What  was  said  in  thejDreceding  section 
in  regard  to  temperature  applies  also  to  the  question  of 
the  best  conditions  for  germination  as  regards  the  supply 
of  moisture.  The  soil  in  which  seeds  grow  out  of  doors 
is  always  moist;  it  rests  with  the  experimenter  to  find 
out  approximately  what  is  the  best  amount  of  moisture. 


EXPERIMENT   II1 

Relation   of   Water  to   Germination.  —  Arrange   seeds   in   several 
vessels  as  follows : 

In  the  first  put  blotting  paper  that  is  barely  moistened ;  on  this 
put  some  dry  seeds. 

In  the  second  put  blotting  paper  that  has  been  barely  moistened ; 
on  this  put  seeds  that  have  been  soaked  for  twenty-four  hours. 

In  the  third  put 
water  enough  to  soak 
the  paper  thor- 
oughly; use  soaked 


In  the  fourth  put 
water  enough  to  half 
cover  the  seeds. 

Place  the  vessels 
where  they  will  have 
same  temperature  and 
note  the  time  of  ger- 
mination. 

Tabulate  your  re- 
sults as  in  the  previ- 
ous experiment. 

10,  Relation  of  the  Air  Supply  to  Germination.  —  If  we 
wish  to  see  how  soaked  seeds  will  behave  with  hardly  any 
air  supply,  it  is  necessary  to  place  them  in  a  bottle  arranged 

1  This  may  be  made  a  home  experiment. 


FIG.  3.  — Soaked  Peas  in  Stoppered  Bottle,  ready 
for  Exhaustion  of  Air. 


THE   SEED   AND   ITS   GERMINATION  11 

as  shown  in  Fig.  3,  exhaust  the  air  by  connecting  the  glass 
tube  with  an  air-pump,  which  is  then  pumped  vigorously, 
and  seal  the  tube  while  the  exhaustion  is  going  on.  The 
sealing  is  best  done  by  holding  a  Bunsen  flame  under  the 
middle  of  the  horizontal  part  of  the  tube.  A  much  easier 
experiment,  which  is  nearly  as  satisfactory,  can,  however, 
be  performed  without  the  air-pump. 

EXPERIMENT   III 

Will   Seeds  Germinate  well  without   a   Good  Supply  of   Air?  — 

Place  some  soaked  seeds  on  damp  blotting  paper  in  the  bottom  of  a 
bottle,  using  seeds  enough  to  fill  it  three-quarters  full,  and  close 
tightly  with  a  rubber  stopper. 

Place  a  few  other  seeds  of  the  same  kind  in  a  second  bottle; 
cover  loosely. 

Place  the  bottles  side  by  side,  so  that  they  will  have  the  same 
conditions  of  light  and  heat.  Watch  for  results,  and  tabulate  as  in 
previous  experiments. 

Most  seeds  will  not  germinate  under  water,  but  those  of  the 
sunflower  will  do  so,  and  therefore  Exp.  Ill  may  be  varied  in  the 
following  manner : 

Remove  tlje  shells  carefully  from  a  considerable  number  of  sun- 
flower seeds.1  Try  to  germinate  one  lot  of  these  in  water  which  has 
been  boiled  in  a  flask  to  remove  the  air,  and  then  cooled  in  the 
same  flask.  Over  the  water,  with  the  seeds  in  it,  a  layer  of  cotton- 
seed oil  about  a  half  inch  deep  is  poured,  to  keep  the  water  from 
contact  with  air.  In  this  bottle  then  there  will  be  only  seeds  and 
air-free  water.  Try  to  germinate  another  lot  of  seeds  in  a  bottle 
half  filled  with  ordinary  water,  also  covered  with  cotton-seed  oil. 
Results? 

r~ 

11.  Germination  involves  Chemical  Changes. —  If  a  ther- 
mometer is  inserted  into  a  jar  of  sprouting  seeds,  for 

1  These  are  really  fruits,  but  the  distinction  is  not  an  important  one  at 
this  time. 


12  FOUNDATIONS   OF   BOTANY 

instance  peas,  in  a  room  at  the  ordinary  temperature,  the 
peas  will  be  found  to  be  warmer  than  the  surrounding 
air.  This  rise  of  temperature  is  at  least  partly  due  to 
the  absorption  from  the  air  of  that  substance  in  it  which 
supports  the  life  of  animals  and  maintains  the  burning  of 
fires,  namely,  oxygen. 

The  union  of  oxygen  with  substances  with  which  it 
can  combine,  that  is  with  those  which  will  burn,  is  called 
oxidation.  This  kind  of  chemical  change  is  universal  in 
plants  and  animals  while  they  are  in  an  active  condition, 
and  the  energy  which  they  manifest  in  their  growth  and 
movements  is  as  directly  the  result  of  the  oxidation  going 
on  inside  them  as  the  energy  of  a  steam  engine  is  the 
result  of  the  burning  of  coal  or  other  fuel  under  its  boiler. 
In  the  sprouting  seed  much  of  the  energy  produced  by 
the  action  of  oxygen  upon  oxidizable  portions  of  its  con- 
tents is  expended  in  producing  growth,  but  some  of  this 
energy  is  wasted  by  being  transformed  into  heat  which 
escapes  into  the  surrounding  soil.  It  is  this  escaping 
heat  which  is  detected  by  a  thermometer  thrust  into  a 
quantity  of  germinating  seeds. 

EXPERIMENT   IV 

Effect  of  Germinating  Seeds  upon  the  Surrounding  Air.  —  When 
Exp.  Ill  has  been  finished,  remove  a  little  of  the  air  from  above  the 
peas  in  the  first  bottle.  This  can  easily  be  done  with  a  rubber  bulb 
attached  to  a  short  glass  tube.  Then  bubble  this  air  through  some 
clear,  filtered  limewater.  Also  blow  the  breath  through  some  lime- 
water  by  aid  of  a  short  glass  tube.  Explain  any  similarity  in 
results  obtained.  (Carbon  dioxide  turns  limewater  milky.)  After- 
wards insert  into  the  air  above  the  peas  in  the  same  bottle  a  lighted 
pine  splinter,  and  note  the  effect  upon  its  flame. 


THE    SEED   AND    ITS   GERMINATION  13 

12.  Other  Proofs  of  Chemical  Action.  —  Besides  the  proof  ->,  t  ^ 
of  chemical  changes  in  germinating  seeds  just  described,   ^^ 
there  are  other  kinds  of  evidence  to  the  same  effect. 

Malt,  which  is  merely  sprouted  barley  with  its  germi- 
nation permanently  stopped  at  the  desired  point  by  the 
application  of  heat,  tastes  differently  from  the  unsprouted 
grain,  and  can  be  shown  by  chemical  tests  to  have  suffered 
a  variety  of  changes.  If  you  can  get  unsprouted  barley 
and  malt,  taste  both  and  see  if  you  can  decide  what  sub- 
stance is  more  abundant  in  the  malt. 

Germinating  kernels  of  corn  undergo  great  alterations 
in  their  structure ;  the  starch  grains  are  gradually  eaten 
away  until  they  are  ragged  and  full  of  holes  and  finally 
disappear. 

13.  The  Embryo  and  its  Development.  —  The  miniature 
plant,  as  it  exists  ready  formed  and  alive  but  inactive  in 
the  seed,  is  called  the  embryo.     In  the  seeds  so  far  ex- 
amined, practically  the  entire  contents  of  the  seed-coats 
consist  of  the  embryo,  but  this  is  not  the  case  with  the 
great  majority  of  seeds,  as  will  be  shown  in  the  following 
chapter. 


CHAPTER   II 
STORAGE   OF  FOOD  IN  THE   SEED 

14.  Food  in  the  Embryo.  —  Squash  seeds  are  not  much 
used  for  human  food,  though  both  these  and  melon  seeds 
are  occasionally  eaten  in  parts  of  Europe ;  but  beans  and 
peas  are  important  articles  of  food.     Whether  the  material 
accumulated  in  the  cotyledons  is  an  aid  to  the  growth  of 
the  young  plant  may  be  learned  from  a  simple  experiment. 

15.  Mutilated  and  Perfect  Seedlings.  —  One  of  the  best 
ways  in  which  to  find  out  the  importance  and  the  special 

use  of  any  part  of 
a  plant  is  to  re- 
move the  part  in 
question  and  see 
how  the  plant  be- 
haves afterward. 

EXPERIMENT  V1 

Are  the  Cotyledons 
of  a  Pea  of  any  Use 
to  the  Seedling  ?  — 

Sprout  several  peas  on 
FIG.  4.  -Germinating  Peas,  growing  in  Water,  one        blotting     aper>   When 
deprived  of  its  Cotyledons. 

the  plumules  appear, 

carefully  cut  away  the  cotyledons  from  some  of  the  seeds.     Place  on 
a  perforated  cork,  as  shown  in  Fig.  4,  one  or  two  seedlings  from 

1  May  be  a  home  experiment. 
14 


STORAGE  OF  FOOD  IN  THE  CELLS         15 

which  the  cotyledons  have  been  cut,  and  as  many  which  have  not 
been  mutilated,  and 'allow  the  roots  to  extend  into  the  water.  Let 
them  grow  for  some  days,  or  even  weeks,  and  note  results. 

16.  Food  stored  in  Seeds  in  Relation  to  Growth  after 

Germination If  two  kinds  of  seeds  of  somewhat  similar 

character,  one  kind  large  and  the  other  small,  are  allowed 
to  germinate  and  grow  side  by  side,  some  important  infer- 
ences may  be  drawn  from  their  relative  rate  of  growth. 

EXPERIMENT   VI1 

Does  the  Amount  of  Material  in  the  Seed  have  anything  to  do  with 
the  Rate  of  Growth  of  the  Seedling  ?  —  Germinate  ten  or  more 
clover  seeds,  and  about  the  same  number  of  peas,  on  moist  blotting 
paper  under  a  bell-jar.  After  they  are  well  sprouted,  transfer  both 
kinds  of  seeds  to  fine  cotton  netting,  stretched  across  wide-mouthed 
jars  nearly  full  of  water.  The  roots  should  dip  into  the  water,  but 
the  seeds  must  not  do  so.  Allow  the  plants  to  grow  until  the  peas 
are  from  four  to  six  inches  high. 

Some  of  the  growth  in  each  case  depends  on  material 
gathered  from  the  air  and  water,  but  most  of  it,  during  the 
very  early  life  of  the  plant,  is  due  to  the  reserve  material 
stored  in  the  seed.  Where  is  it  in 
the  seeds  so  far  studied  ?  Proof  ? 

17.  Storage  of  Food  outside  of 
the  Embryo.  —  In  very  many  cases 
the  cotyledons  contain  little  food, 

but  there    is   a  Supply   of    it  Stored    FIG.  5.  — Seeds  with  Endosperm, 
,  ,  ,        .  ,  -1,1  Longitudinal  Sections. 

in  the  seed  beside  or  around  them 

I,  asparagus  (magnified). 
(FlgS.  2,  5,  aild  6).  II,  poppy  (magnified). 

18.  Examination  of  the  Four-o'clock  Seed.  —  Examine  the  exter- 
nal surface  of  a  seed2  of  the  four-o'clock,  and  try  the  hardness  of 

1  May  be  a  home  experiment.         2  Strictly  speaking,  a  fruit. 


16 


FOUNDATIONS    OF   BOTANY 


the  outer  coat  by  cutting  it  with  a  knife.  From  seeds  which  have 
been  soaked  in  water  at  least  twenty-four  hours  peel  off  the  coatings 
and  sketch  the  kernel.  Make  a  cross-section  of  one  of  the  soaked 
seeds  which  has  not  been  stripped  of  its  coatings,  and  sketch  the  sec- 
tion as  seen  with  the  magnifying  glass,  to  show  the  parts,  especially 
the  two  cotyledons,  lying  in  close  contact  and  encircling  the  white, 
starchy-looking  endosperm.1 

The  name  endosperm  is  applied  to  food  stored  in  parts  of  the 
seed  other  than  the  embryo.2  With  a  mounted  needle  pick  out  the 
little  almost  spherical  mass  of  endosperm  from  inside  the  cotyledons 
of  a  seed  which  has  been  deprived  of 
its  coats,  and  sketch  the  embryo,  noting 
how  it  is  curved  so  as  to  enclose  the 
endosperm  almost  completely. 

19,  Examination  of  the-  Kernel  of  In- 
dian Corn.  —  Soak  some  grains  of  large 
yellow  field  corn  3  for  about  three  days. 

Sketch  an  unsoaked  kernel,  so  as  to 
show  the  grooved  side,  where  the  germ 
lies.  Observe  how  this  groove  has  be- 
come partially  filled  up  in  the  soaked 
kernels. 

Remove    the  thin,  tough  skin  from 


FIG.  6.  —  Lengthwise  Section  of 

Grain  of  Corn.     (Magnified 

about  three  times.) 


tion  of  food  from  it ;    r, 
primary  root. 


„,  yellow,  oily  part  of  endosperm-,  one  of  the  latter,  and  notice  its  transpar- 
w,  white,  starchy  part  of  en-  ency.  This  skin  —  the  bran  of  unsifted 
dosperm  ;  p,  plumule  ;  *,  the  CQrn  meal  _  doeg  not  exactly  correspond 
shield  (cotyledon),  in  contact  . 

with  the  endosperm  f  or  absorp-  to  the  testa  and  inner  coat  of  ordinary 
the  seeds,  since  the  kernel  of  corn,  like  all 
other  grains  (and  like  the  seed  of  the 
four-o'clock),  represents  not  merely  the  seed,  but  also  the  se,ed-vessel 
in  which  it  was  formed  and  grew,  and  is  therefore  a  fruit.  / 

1  Buckwheat  furnishes  another  excellent  study  in  seeds  with  endosperm. 
Like  that  of  the  four-o'clock,  it  is,  strictly  speaking,  a  fruit ;  so  also  is  a  grain 
of  corn. 

2  In  the  squash  seed  the  green  layer  which  covered  the  embryo  represents 
the  remains  of  the  endosperm. 

3  The  varieties  with  long,  flat  kernels,  raised  in  the  Middle  and  Southern 
States  under  the  name  of  "  dent  corn,"  are  the  best. 


STORAGE   OF  FOOD   IX  THE    SEED  17 

Cut  sections  of  the  soaked  kernels,  some  transverse,  some  length- 
wise and  parallel  to  the  flat  surfaces,  some  lengthwise  and  at  right 
angles  to  the  flat  surfaces.  Try  the  effect  of  staining  some  of  these 
sections  with  iodine  solution. 

Make  a  sketch  of  one  section  of  each  of  the  three  kinds,  and  label 
the  dirty  white  portion,  of  cheesy  consistency,  embryo  ;  and  the  yel- 
low portions,  and  those  which  are  white  and  floury,  endosperm. 

Chip  off  the  endosperm  from  one  kernel  so  as  to  remove  the 
embryo  free  from  other  parts.1  Notice  its  form,  somewhat  triangular 
in  outline,  sometimes  nearly  the  shape  of  a  beechnut,  in  other  speci- 
mens nearly  like  an  almond. 

Estimate  what  proportion  of  the  entire  bulk  of  the  soaked  kernel 
is  embryo. 

Split  the  embryo  lengthwise  so  as  to  show  the  slender,  somewhat 
conical  plumule.2 

20.  Corn  Seedlings  deprived  of  Endosperm — An  experi- 
ment parallel  to  No.  V  serves  to  show  the  function  and 
the  importance  of  the  endosperm  of  Indian  corn. 

EXPERIMENT   VII 

Of  how  much  Use  to  the  Corn  Seedling  is  the  Endosperm  ?  —  Sprout 
kernels  of  corn  on  blotting  paper.  When  they  get  fairly  started, 
cut  away  the  endosperm  carefully  from  several  of  the  seeds.  Sus- 
pend on  mosquito  netting  on  the  surface  of  water  in  the  same  jar 
two  or  three  seedlings  which  have  had  their  endosperm  removed,  and 
as  many  which  have  not  been  mutilated.  Let  them  grow  for  some 
weeks,  and  note  results. 

21.  Starch Most     common    seeds     contain    starch. 

Every  one  knows  something  about  the  appearance  of  ordi- 

1  The  embryo  may  be  removed  with  great  ease  from  kernels  of  rather  ma- 
ture green  corn.    Boil  the  corn  for  about  twenty  minutes  on  the  cob,  then  pick 
the  kernels  off  one  by  one  with  the  point  of  a  knife.    They  may  be  preserved 
indefinitely  in  alcohol  of  50  or  75%. 

2  The  teacher  may  well  consult  Figs.  56-61,  inclusive,  in  Gray's  Structural 
Botany. 


18  FOUNDATIONS  OF  BOTANY 

nary  commercial  starch  as  used  in  the  laundry,  and  as 
sold  for  food  in  packages  of  cornstarch.  When  pure  it 
is  characterized  not  only  by  its  lustre,  but  also  by  its 
peculiar  velvety  feeling  when  rubbed  between  the  fingers. 

22.  The  Starch  Test It  is  not  always  easy  to  recog- 
nize at  sight  the  presence  of  starch  as  it  occurs  in  seeds, 
but  it  may  be  detected  by  a  very  simple  chemical  test, 
namely,  the  addition  of  a  solution  of  iodine.1 

EXPERIMENT   VIII2 

Examination  of  Familiar  Seeds  with  Iodine.  —  Cut  in  two  with  a 
sharp  knife  the  seeds  to  be  experimented  on,  then  pour  on  each,  drop 
by  drop,  some  of  the  iodine  solution.  Only  a  little  is  necessary; 
sometimes  the  first  drop  is  enough. 

If  starch  is  present,  a  blue  color  (sometimes  almost  black)  will 
appear.  If  no  color  is  obtained  in  this  way,  boil  the  pulverized 
seeds  for  a  moment  in  a  few  drops  of  water,  and  try  again. 

Test  in  this  manner  corn,  wheat  (in  the  shape  of  flour),  oats  (in 
oatmeal),  barley,  rice,  buckwheat,  flax,  rye,  sunflower,  four-o'clock, 
morning-glory,  mustard  seed,  beans,  peanuts,  Brazil-nuts,  hazelnuts, 
and  any  other  seeds  that  you  can  get.  Report  your  results  in  tabu- 
lar form  as  follows  :  . 

MUCH  STARCH  LITTLE  STARCH  No  STARCH 

Color :  blackish  or         Color :  pale  blue  or         Color  :  brown,  orange, 
,  dark  blue.  greenish.  or  yellowish. 

23.  Microscopical  Examination  of  Starch.3  —  Examine  starch  in 
water  with  a  rather  high  power  of  the  microscope  (not  less  than  200 
diameters). 

1  The  tincture  of  iodine  sold  at  the  drug-stores  will  do,  but  the  solution 
prepared  as  directed  in  the  Handbook  answers  better.  This  may  be  made  up 
in  quantity,  and  issued  to  the  pupils  in  drachm  vials,  to  be  taken  home  and 
used  there,  if  the  experimenting  must  be  done  outside  of  the  laboratory  or  the 
schoolroom.  2  May  be  a  home  experiment. 

8  At  this  point  the  teacher  should  give  a  brief  illustrated  talk  on  the  con- 
struction and  theory  of  the  compound  microscope. 


STORAGE  OF  FOOD  IN  THE  SEED 


19 


Pulp  scraped  from  a  potato,  that  from  a  canna  rootstock,  wheat 
flour,  the  finely  powdered  starch  sold  under  the  commercial  name  of 
"cornstarch"  for  cooking,  oat- 
meal, and  buckwheat  finely  pow- 
dered in  a  mortar,  will  furnish 
excellent  examples  of  the  shape 
and  markings  of  starch  grains. 
Sketch  all  of  the  kinds  exam- 
ined, taking  pains  to  bring  out 
the  markings.1  Compare  the 
sketches  with  Figs.  7  and  8. 

With  a  medicine-dropper  or  a 
very  small  pipette  run  in  a  drop       FIG.  7.  —  Canna  starch.    (Magnified 
of  iodine  solution  under  one  edge 

of  the  cover-glass,  at  the  same  time  withdrawing  a  little  water  from 
the   margin   opposite  by   touching  to   it  a  bit  of   blotting  paper. 


FIG.  8.  — Section  through  Exterior  Part  of  a  Grain  of  Wheat. 

c,  cuticle  or  outer  layer  of  bran  ;  ep,  epidermis  ;  m,  layer  beneath  epidermis  ;  gu, 
sch,  layers  of  hull  next  to  seed-coats ;  br,  n,  seed-coats ;  Kl,  layer  containing 
proteid  grains  ;  st,  cells  of  the  endosperm  filled  with  starch.  (Greatly  magnified.) 

1  The  markings  will  be  seen  more  distinctly  if  care  is  taken  not  to  admit 
too  much  light  to  the  object.  Rotate  the  diaphragm  beneath  the  stage  of  the 
microscope,  or  otherwise  regulate  the  supply  of  light,  until  the  opening  is 
found  which  gives  the  best  effect. 


20  FOUNDATIONS   OF   BOTANY 

Examine  again  and  note  the  blue  coloration  of  the  starch  grains  and 
the  unstained  or  yellow  appearance  of  other  substances  in  the  field. 
Cut  very  thin  slices  from  beans,  peas,  or  kernels  of  corn  ;  mount  in 
water,  stain  as  above  directed,  and  draw  as  seen  under  the  microscope. 
Compare  with  Figs.  7  and  S.1  Note  the  fact  that  the  starch  is  not 
packed  away  in  the  seeds  in  bulk,  but  that  it  is  enclosed  in  little 
chambers  or  cells. 

24,  Plant-Cells.  —  Almost  all  the  parts  of  the  higher 
plants  are  built  up  of  little  separate  portions  called  cells. 
\/The  cell  is  the  unit  of  plant-structure,  and  bears  some- 
thing the  same  relation  to  the  plant  of  which  it  is  a  part 
that  one  cell  of  a  honeycomb  does  to  the  whole  comb. 
But  this  comparison  is  not  a  perfect  one,  for  neither  the 
waxen  wall  of  the  honeycomb-cell  nor  the  honey  within  it 
is  alive,  while  every  plant-cell  is  or  has  been  alive.  And 
even  the  largest  ordinary  honeycomb  consists  of  only  a 
few  hundred  cells,  while  a  large  tree  is  made  up  of  very 
many  millions  of  cells.  The  student  must  not  conceive 
of  the  cell  as  merely  a,  little  chamber  or  enclosure.  The 
living,  more  or  less  liquid,  or  mucilage-like,  or  jelly-like 
substance  known  as  protoplasm,  which  forms  a  large  portion 
of  the  bulk  of  living  and  growing  cells,  is  the  all-important 
part  of  such  a  cell.  Professor  Huxley  has  well  called 
this  substance  "the  physical  basis  of  life."  Cells  are  of 
all  shapes  and  sizes,  from  little  spheres  a  ten-thousandth 
of  an  inch  or  less  in  diameter  to  slender  tubes,  such  as 
fibers  of  cotton,  several  inches  long.  To  get  an  idea  of 
the  appearance  of  some  rather  large  cells,  scrape  a  little 
pulp  from  a  ripe,  mealy  apple,  and  examine  it  first  with 

1  The  differentiation  between  the  starch  grains,  the  other  cell-contents, 
and  the  cell-walls  will  appear  better  in  the  drawings  if  the  starch  grains  are 
sketched  with  blue  ink. 


STORAGE    OF   FOOD   IN   THE   SEED  21 

a  strong  magnifying  glass,  then  with  a  moderate  power  of 
the  compound  microscope.  To  see  how  dead,  dry  cell- 
walls,  with  nothing  inside  them,  look,  examine  (as  before) 
a  very  thin  slice  of  elder  pith,  sunflower  pith,  or  pith  from 
a  dead  cornstalk.  Look  also  at  the  figures  in  Chapter  VI 
of  this  book.  Notice  that  the  simplest  plants  (Chapter  XX) 
consist  of  a  single  cell  each.  The  study  of  the  structure 
of  plants  is  the  study  of  the  forms  which  cells  and  groups 
of  cells  assume,  and  the  study  of  plant  physiology  is  the 
study  of  what  cells  and  cell  combinations  do. 

25.  Absorption  of  Starch  from  the  Cotyledons.  —  Examine  with 
the  microscope,  using  a  medium  power,  soaked  beans  and  the  cotyle- 
dons from  seedlings  that  have  been  growing  for  three  or  four  weeks. 
Stain  the  sections  with  iodine  solution,  and  notice  how  completely 
the  clusters  of  starch  grains  that  filled  most  of  the  cells  of  the  un- 
sprouted  cotyledons  have  disappeared  from  the  shriveled  cotyledons 
of  the  seedlings.     A  few  grains  may  be  left,  but  they  have  lost  their 
sharpness  of  outline. 

26.  Oil.  —  The    presence    of    oil    in    any   considerable 
quantity  in  seeds  is  not  as  general  as  is  the  presence  of 
starch,  though  in  many  common  seeds  there   is  a  good 
deal  of  it. 

Sometimes  the  oil  is  sufficiently  abundant  to  make  it 
worth  while  to  extract  it  by  pressure,  as  is  done  with  flax- 
seed,  cotton-seed,  the  seeds  of  some  plants  of  the  cress 
family,  the  "  castor  bean,"  and  other  seeds. 

27.  Dissolving  Oil  from  Ground  Seeds.  —  It  is  not  possi- 
ble easily  to  show  a  class  how  oil  is  extracted  from  seeds 
by  pressure ;  but  there  are  several  liquids  which  readily 
dissolve  oils  and  yet  have  no  effect  on  starch  and  most  of 
the  other  constituents  of  seeds. 


22  FOUNDATIONS  OF  BOTANY 


EXPERIMENT    IX 

Extraction  of  Oil  by  Ether  or  Benzine.  —  To  a  few  ounces  of 
ground  flaxseed  add  an  equal  volume  of  ether  or  benzine.  Let  it 
stand  ten  or  fifteen  minutes  and  then  filter.  Let  the  liquid  stand  in 
a  saucer  or  evaporating  dish  in  a  good  draught  till  it  has  lost  the 
odor  of  the  ether  or  benzine. 

Describe  the  oil  which  you  have  obtained. 

Of  what  use  would  it  have  been  to  the  plant? 

If  the  student  wishes  to  do  this  experiment  at  home  for  himself, 
he  should  bear  in  mind  the  following : 

Caution.  —  Never  handle  benzine  or  ether  near  a  flame  or  stove. 

A  much  simpler  experiment  to  find  oil  in  seeds  may  readily  be 
performed  by  the  pupil  at  home.  Put  the  material  to  be  studied,  e.g., 
flaxseed  meal,  corn  meal,  wheat  flour,  cotton-seed  meal,  buckwheat 
flour,  oatmeal,  and  so  on,  upon  little  labeled  pieces  of  white  paper, 
one  kind  of  flour  or  meal  on  each  bit  of  paper.  Place  all  the  papers, 
with  their  contents,  on  a  perfectly  clean  plate,  free  from  cracks,  or 
on  a  clean  sheet  of  iron,  and  put  this  in  an  oven  hot  enough  nearly 
(but  not  quite)  to  scorch  the  paper.  After  half  an  hour  remove  the 
plate  from  the  oven,  shake  off  the  flour  or  meal  from  each  paper,  and 
note  the  results,  a  more  or  less  distinct  grease  spot  showing  the 
presence  of  oil,  or  the  absence  of  any  stain  that  there  was  little  or 
no  oil  in  the  seed  examined. 

28.  Albuminous  Substances.  —  Albuminous  substances 
or  proteids  occur  in  all  seeds,  though  often  only  in  small 
quantities.  They  have  nearly  the  same  chemical  compo- 
sition as  white  of  egg  and  the  curd  of  milk  among  animal 
substances,  and  are  essential  to  the  plant,  since  the  living 
and  growing  parts  of  all  plants  contain  large  quantities  of 
proteid  material. 

Sometimes  the  albuminous  constituents  of  the  seed  occur 
in  more  or  less  regular  grains  (Fig.  8,  at  Kl) . 

But  much  of  the  proteid  material  of  seeds  is  not  in  any 


STORAGE   OF  FOOD   IN  THE    SEED  23 

form  in  which  it  can  be  recognized  under  the  microscope. 
One  test  for  its  presence  is  the  peculiar  smell  which  it 
produces  in  burning.  Hair,  wool,  feathers,  leather,  and 
lean  meat  all  produce  a  well-known  sickening  smell  when 
scorched  or  burned,  and  the  similarity  of  the  proteid  mate- 
rial in  such  seeds  as  the  bean  and  pea  to  these  substances 
is  shown  by  the  fact  that  scorching  beans  and  similar 
seeds  give  off  the  familiar  smell  of  burnt  feathers. 

29.  Chemical  Tests   for   Proteids. — All  proteids   (and 
very  few  other  substances)  are   turned  yellow  by  nitric 
acid,  and  this  yellow  color  becomes  deeper  or  even  orange 
when  the  yellowish  substance  is  moistened  with  ammonia. 
They  are  also  turned  yellow  by  iodine  solution.     Most 
proteids  are  turned  more  or  less  red  by  the  solution  of 
nitrate  of  mercury  known  as  Millon's  reagent.1 

EXPERIMENT  X 

Detection  of  Proteids  in  Seeds.  —  Extract  the  germs  from  some 
soaked  kernels  of  corn  and  bruise  them;  soak  some  wheat-germ  meal 
for  a  few  hours  in  warm  water,  or  wash  the  starch  out  of  wheat- 
flour  dough ;  reserving  the  latter  for  use,  place  it  in  a  white  saucer  or 
porcelain  evaporating  dish,  and  moisten  well  with  Millon's  reagent 
or  with  nitric  acid ;  examine  after  fifteen  minutes. 

30.  The  Brazil-Nut  as  a  Typical  Oily  Seed.  —  Not  many 
familiar  seeds  are  as  oily  as  the  Brazil-nut.     Its  large  size 
makes  it  convenient  for  examination,  and  the  fact  that  this 
nut  is  good  for  human  food  makes  it  the  more  interesting 
to  investigate  the  kinds  of  plant-food  which  it  contains. 

1  See  Handbook. 


24  FOUNDATIONS   OF   BOTANY 


EXPERIMENT  XI1 

Testing  Brazil-Nuts  for  Plant-Foods.  —  Crack  fifteen  or  twenty 
Brazil-nuts,  peel  off  the  brown  coating  from  the  kernel  of  each,  and 
then  grind  the  kernels  to  a  pulp  in  a  mortar.  Shake  up  this  pulp 
with  ether,  pour  upon  a  paper  filter,  and  wash  with  ether  until  the 
washings  when  evaporated  are  nearly  free  from  oil.  The  funnel 
containing  the  filter  should  be  kept  covered  as  much  as  possible 
until  the  washing  is  finished.  Evaporate  the  filtrate  to  procure  the 
oil,  which  may  afterwards  be  kept  in  a  glass-stoppered  bottle.  Dry 
the  powder  which  remains  on  the  filter  and  keep  it  in  a  wide- 
mouthed  bottle.  Test  portions  of  this  powder  for  proteids  and  for 
starch.  Explain  the  results  obtained. 

31.  Other  Constituents  of  Seeds.  —  Besides  the  substances 
above  suggested,  others  occur  in  different  seeds.  Some 
of  these  are  of  use  in  feeding  the  seedling,  others  are  of 
value  in  protecting  the  seed  itself  from  being  eaten  by 
animals  or  in  rendering  it  less  liable  to  decay.  In  such 
seeds  as  that  of  the  nutmeg,  the  essential  oil  which  gives 
it  its  characteristic  flavor  probably  makes  it  unpalatable 
to  animals  and  at  the  same  time  preserves  it  from  decay. 

Date  seeds  are  so  hard  and  tough  that  they  cannot  be 
eaten  and  do  not  readily  decay.  Lemon,  orange,  horse- 
chestnut  and  buckeye  seeds  are-  too  bitter  to  be  eaten,  and 
the  seeds  of  the  apple,  cherry,  peach,  and  plum  are  some- 
what bitter. 

The  seeds  of  larkspur,  thorn-apple,1  croton,  the  castor- 
oil  plant,  nux  vomica,  and  many  other  kinds  of  plants 
contain  active  poisons. 

1  Datura,  commonly  called  "  Jimpson  weed." 


CHAPTER    III 


MOVEMENTS,   DEVELOPMENT,   AND   MORPHOLOGY  OF 
THE   SEEDLING 

32,  How  the  Seedling  breaks  Ground.  —  As  the  student 
has  already  learned  by  his  own  observations,  the  seedling 
does  not  always  push  its  way  straight  out  of  the  ground. 
Corn,  like  all  the  other  grains  and  grasses,  it  is  true,  sends 
a  tightly  rolled,  pointed  leaf  vertically  upward  into  the 
air.  But  the  other  seedlings  examined  usually  will  not 
be  found  to  do  anything  of  the  sort.  The  squash  seedling 
is  a  good  one  in  which  to  study  what  may 
be  called  the  arched  hypocotyl 
type  of  germination.  If  the 
seed  when  planted  is  laid  hori- 


A  B  c  D          E 

FIG.  9.  — Successive  Stages  in  the  Life  History  of  the  Squash  Seedling. 

GG,  the  surface  of  the  ground  ;  r,  primary  root ;  r',  secondary  root ;  c,  hypocotyl ; 
a,  arch  of  hypocotyl ;  co,  cotyledons. 

zontally  on  one  of  its  broad  surfaces,  it  usually  goes  through 
some  such  changes  of  position  as  are  shown  in  Fig.  9. 

25 


26  FOUNDATIONS   OF   BOTANY 

The  seed  is  gradually  tilted  until,  at  the  time  of  their 
emergence  from  the  ground  (at  (7),  the  cotyledons  are 
almost  vertical.  The  only  part  above  the  ground-line  6r,  6r, 
at  this  period,  is  the  arched  hypocotyl.  Once  out  of  ground, 
the  cotyledons  soon  rise,  until  (at  E)  they  are  again  ver- 
tical, but  with  the  other  end  up  from  that  which  stood 
highest  in  C.  Then  the  two  cotyledons  separate  until 
they  once  more  lie  horizontal,  pointing  away  from  each 
other. 

Can  you  suggest  any  advantage  which  the  plant  derives 
from  having  the  cotyledons  dragged  out  of  the  ground 
rather  than  having  them  pushed  out,  tips  first  ? 

33.  Cause  of  the  Arch.  —  It  is  evident  that  a  flexible 
object  like  the  hypocotyl,  when  pushed  upward  through  the 
earth,  might  easily  be  bent  into  an  arch  or  loop.    Whether 
the  shape  which  the  hypocotyl  assumes  is  wholly  caused 
by  the  resistance  of  the  soil  can  best  be  ascertained  by 
an  experiment. 

EXPERIMENT   XII 

Is  the  Arch  of  the  Hypocotyl  due  to  the  Pressure  of  the  Soil  on  the 
Rising  Cotyledons  ?  —  Sprout  some  squash  seeds  on  wet  paper  under 
a  bell-glass,  and  when  the  root  is  an  inch  or  more  long,  hang  several 
of  the  seedlings,  roots  down,  in  little  stirrups  made  of  soft  twine, 
attached  by  beeswax  and  rosin  mixture  to  the  inside  of  the  upper 
part  of  a  bell-glass.  Put  the  bell-glass  on  a  large  plate  or  a  sheet  of 
glass  on  which  lies  wet  paper  to  keep  the  air  moist.  Note  whether 
the  seedlings  form  hypocotyl  arches  at  all  and,  if  so,  whether  the 
arch  is  more  or  less  perfect  than  that  formed  by  seedlings  growing 
in  earth,  sand,  or  sawdust. 

34.  What  pushes  the  Cotyledons   up?  —  A  very  little 
study  of  any  set  of  squash  seedlings,  or  even  of  Fig.  9,  is 


MORPHOLOGY   OF  THE   SEEDLING  27 

sufficient  to  show  that  the  portion  of  the  plant  where 
roots  and  hypocotyl  are  joined  neither  rises  nor  sinks,  but 
that  the  plant  grows  both  ways  from  this  part  (a  little 
above  rr  in  Fig.  9,  A  and  B).  It  is  evident  that  as  soon  as 
the  hypocotyl  begins  to  lengthen  much  it  must  do  one  of 
two  things  :  either  push  the  cotyledons  out  into  the  air  or 
else  force  the  root  down  into  the  ground  as  one  might 
push  a  stake  down.  What  changes  does  the  plantlet 
undergo,  in  passing  from  the  stage  shown  at  A  to  that 
of  B  and  of  6y,  making  it  harder  and  harder  for  the  root 
to  be  thrust  downward? 

35.  Use  of  the  Peg.  —  Squash  seedlings  usually  (though 
not  always)  form  a  sort  of  knob  on  the  hypocotyl.    This  is 
known  as  the  peg.     Study  a  good  many  seedlings  and  try 
to  find  out  what  the  lengthening  of  the  hypocotyl,  between 
the  peg  and  the  bases  of  the  cotyledons,  does  for  the  little 
plant.     Set  a  lot  of  squash  seeds,  hilum  down,  in  moist 
sand  or  sawdust  and  see  whether  the  peg  is  more  or  less 
developed  than  in  seeds  sprouted  lying  on  their  sides,  and 
whether  the  cotyledons  in  the  case  of  the  vertically  planted 
seeds  usually  come  out  of  the  ground  in  the  same  condi- 
tion as  do  those  shown  in  Fig.  9. 

36.  Discrimination  between  Root  and  Hypocotyl.  —  It  is 
not  always  easy  to  decide  by  their  appearance   and  be- 
havior what  part  of  the  seedling  is  root  and  what  part  is 
hypocotyl.     In  a  seedling  visibly  beginning  to  germinate, 
the  sprout,  as  it  is  commonly  called,  which  projects  from 
the  seed  might  be  either  root  or  hypocotyl  or  might  consist 
of  both  together,  so  far  as  its  appearance  is  concerned.    A 
microscopic  study  of  the  cross-section  of  a  root,  compared 
with  one  of  the  hypocotyl,  would  show  decided  differences 


28  FOUNDATIONS   OF  BOTANY 

of  structure  between  the  two.  Their  mode  of  growth  is 
also  different,  as  the  pupil  may  infer  after  he  has  tried 
Exp.  XIV. 

37.  Discrimination  by  Staining.  —  For  some  reason,  per- 
haps because  the  skin  or  epidermis  of  the  young  root  is 
not  so  water-proof  as  that  of  the  stem,  the  former  stains 
more  easily  than  the  latter  does. 

EXPERIMENT   XIII 

The  Permanganate  Test.  —  Make  a  solution  of  potassium  perman- 
ganate in  water,  by  adding  about  four  parts,  by  weight,  of  the  crystal- 
lized permanganate  to  100  parts  of  water.  Drop  into  the  solution 
seedlings,  e.g.,  of  all  the  kinds  that  have  been  so  far  studied,  each  in 
its  earliest  stage  of  germination  (that  is,  when  the  root  or  hypocotyl 
has  pushed  out  of  the  seed  half  an  inch  or  less),  and  also  at  one  or 
two  subsequent  stages.  After  the  seedlings  have  been  in  the  solu- 
tion from  three  to  five  minutes,  or  as  soon  as  the  roots  are  consider- 
ably stained,  pour  off  (and  save)  the  solution  and  rinse  the  plants 
with  plenty  of  clear  water.  Sketch  one  specimen  of  each  kind,  col- 
oring the  brown-stained  part,  which  is  root,  in  some  way  so  as  to 
distinguish  it  from  the  unstained  hypocotyl.  Note  particularly  how 
much  difference  there  is  in  the  amount  of  lengthening  in  the  several 
kinds  of  hypocotyl  examined.  Decide  whether  the  peg  of  the  squash 
seedling  is  an  outgrowth  of  hypocotyl  or  of  root. 

38.  Disposition  made  of  the  Cotyledons.  —  As  soon  as 
the  young  plants  of  squash,  bean,  and  pea  have  reached 
a  height  of  three  or  four  inches  above  the  ground  it  is 
easy  to  recognize  important    differences  in  the  way  in 
which  they  set  out  in  life. 

The  cotyledons  of  the  squash  increase  greatly  in  sur- 
face, acquire  a  green  color  and  a  generally  leaf-like  appear- 
ance, and,  in  fact,  do  the  work  of  ordinary  leaves.  In 


MORPHOLOGY   OF   THE   SEEDLING  29 

such  a  case  as  this  the  appropriateness  of  the  name  seed- 
leaf  is  evident  enough,  —  one  recognizes  at  sight  the  fact 
that  the  cotyledons  are  actually  the  plant's  first  leaves. 
In  the  bean  the  leaf-like  nature  of  the  cotyledons  is  not 
so  clear.  They  rise  out  of  the  ground  like  the  squash 
cotyledons,  but  then  gradually  shrivel  away,  though  they 
may  first  turn  green  and  somewhat  leaf-like  for  a  time. 

In  the  pea  (as  in  the  acorn,  the  horse-chestnut,  and 
many  other  seeds)  we  have  quite  another  plan,  the  under- 
ground type  of  germination.  Here  the  thick  cotyledons 
no  longer  rise  above  ground  at  all,  because  they  are  so 
gorged  with  food  that  they  could  never  become  leaves ; 
but  the  young  stem  pushes  rapidly  up  from  the  surface 
of  the  soil. 

The  development  of  the  plumule  seems  to  depend  some- 
what on  that  of  the  cotyledons.  The  squash  seed  has 
cotyledons  which  are  not  too  thick  to  become  useful  leaves, 
and  so  the  plant  is  in  no  special  haste  to  get  ready  any 
other  leaves.  The  plumule,  therefore,  cannot  be  found 
with  the  magnifying  glass  in  the  unsprouted  seed,  and  is 
almost  microscopic  in  size  at  the  time  when  the  hypocotyl 
begins  to  show  outside  of  the  seed-coats. 

In  the  bean  and  pea,  on  the  other  hand,  since  the  cotyle- 
dons cannot  serve  as  foliage  leaves,  the  later  leaves  must 
be  pushed  forward  rapidly.  In  the  bean  the  first  pair  are 
already  well  formed  in  the  seed.  In  the  pea  they  cannot 
be  clearly  made  out,  since  the  young  plant  forms  several 
scales  on  its  stem  before  it  produces  any  full-sized  leaves^ 
and  the  embryo  contains  only  hypocotyl,  cotyledons,  and  a 
sort  of  knobbed  plumule,  well  developed  in  point  of  size, 
representing  the  lower  scaly  part  of  the  stem. 


30  FOUNDATIONS   OF  BOTANY 

39.  Root,  Stem,  and  Leaf.  —  By  the  time  the  seedling  is 
well  out  of  the  ground  it,  in  most  cases,  possesses  the  three 
kinds  of  vegetative  organs,  or  parts  essential  to  growth,  of 
ordinary  flowering  plants,  i.e.,  the  root,  stem,  and  leaf,  or, 
as  they  are  sometimes  classified,  root  and  shoot.     All  of 
these  organs   may  multiply  and  increase  in  size  as  the 
plant  grows   older,   and  their  mature    structure   will  be 
studied  in  later  chapters,  but  some  facts  concerning  them 
can  best  be  learned  by  watching  their  growth  from  the 
outset. 

40.  Young  Roots  grown  for  Examination.  —  Roots  grow- 
ing in  sand  or  ordinary  soil  cling  to  its  particles  so  tena- 
ciously that  they  cannot  easily  be  studied,  and  those  grown 
in  water  have  not  quite  the  same  form  as  soil-roots.    Roots 
grown  in  damp  air  are  best  adapted  for  careful  study. 

41.  Elongation  of  the  Root.  —  We  know  that  the  roots 
of  seedlings  grow  pretty  rapidly  from  the  fact  that  each 
day  finds  them   reaching  visibly  farther  down  into  the 
water  or  other  medium  in  which  they  are  planted.     A 
sprouted  Windsor  bean  in  a  vertical  thistle-tube  will  send 
its  root  downward  fast  enough  so  that  ten  minutes'  watch- 
ing through  the  microscope  will  suffice  to  show  growth. 
To  find  out  just  where  the  growth  goes  on  requires  a 
special  experiment. 

EXPERIMENT   XIV 

In  what  Portions  of  the  Root  does  its  Increase  in  Length  take  Place  ? 
—  Sprout  some  peas  on  moist  blotting  paper  in  a  loosely  covered  tum- 
bler. When  the  roots  are  one  and  a  half  inches  or  more  long,  mark 
them  along  the  whole  length  with  little  dots  made  with  a  bristle 
dipped  in  water-proof  India  ink,  or  a  fine  inked  thread  stretched  on 
a  little  bow  of  whalebone  or  brass  wire. 


MORPHOLOGY   OF   THE   SEEDLING  31 

Transfer  the  plants  to  moist  blotting  paper  under  a  bell-glass  or 
an  inverted  battery  jar  and  examine  the  roots  at  the  end  of  twenty- 
four  hours  to  see  along  what  portions  their  length  has  increased ; 
continue  observations  on  them  for  several  days. 

42.  Root-Hairs.  —  Barley,   oats,   wheat,  red  clover,  or 
buckwheat   seeds    soaked    and    then   sprouted    on    moist 
blotting  paper  afford  convenient'  material    for   studying 
root-hairs.     The  seeds  may  be  kept  covered  with  a  watch-, 
glass  or  a  clock-glass  while  sprouting.     After  they  have 
begun    to    germinate    well,   care    must  be    taken   not   to 
have  them  kept  in  too  moist  an  atmosphere,  or  very  few 
root-hairs    will   be    formed.      Examine    with   the    magni- 
fying  glass   those   parts   of   the  root  which   have   these 
appendages. 

Try  to  find  out  whether  all  the  portions  of  the  root  are 
equally  covered  with  hairs  and,  if  not,  where  they  are 
most  abundant.  (See  also  Sect.  53.) 

The  root-hairs  in  plants  growing  under  ordinary  condi- 
tions are  surrounded  by  the  moist  soil  and  wrap  them- 
selves around  microscopical  particles  of  earth  (Fig.  11). 
Thus  they  are  able  rapidly  to  absorb  through  their  thin 
walls  the  soil-water,  with  whatever  mineral  substances  it 
has  dissolved  in  it. 

43.  The  Young  Stem.  —  The  hypocotyl,  or  portion  of 
the  stem  which  lies  below  the  cotyledons,  is  the  earliest 
formed  portion  of  the  stem.     Sometimes  this  lengthens  but 
little ;  often,  however,  as  the  student  knows  from  his  own 
observations,  the  hypocotyl  lengthens  enough  to  raise  the 
cotyledons  well  above  ground,  as  in  Fig.  10. 

The  later  portions  of  the  stem  are  considered  to  be 
divided  into  successive  nodes,  — places  at  which  a  leaf  (or 


32 


FOUNDATIONS   OF  BOTANY 


a  scale  which  represents  a  leaf)  appears;  and  internodes, — 
portions  between  the  leaves./ 

The  student  should  watch  the  growth  of  a  seedling 
bean  or  pea  and  ascertain  by  actual  measurements  whether 
the  internodes  lengthen  after  they  have  once  been  formed, 
and  if  so,  for  how  long  a  time  the  increase  continues. 


FIG.  10.  FIG.  11. 

FIG.  10.  —  A  Turnip  Seedling,  with  the  Cotyledons  developed  into  Temporary  Leaves. 
h,  root-hairs  from  the  primary  root ;   bf  bare  portion  of  the  root,  on  which  no 
hairs  have  as  yet  been  produced. 

FIG.  11.  —Cross-Section  of  a  Koot, a  good  deal  magnified,  showing  root-hairs  attached 
to  particles  of  soil,  and  sometimes  enwrapping  these  particles. 

44,  The  First  Leaves.  —  The  cotyledons  are,  as  already 
explained,  the  first  leaves  which  the  seedling  possesses,  — 
even  if  a  plumule  is  found  well  developed  in  the  seed,  it 
was  formed  after  the  cotyledons.  In  those  plants  which 
have  so  much  food  stored  in  the  cotyledons  as  to  render 
these  unfit  ever  to  become  useful  foliage  leaves,  there  is 
little  or  nothing  in  the  color,  shape,  or  general  appearance 


MORPHOLOGY   OF   THE   SEEDLING  33 

of  the  cotyledon  to  make  one  think  it  really  a  leaf,  and  it 
is  only  by  studying  many  cases  that  the  botanist  is  enabled 
to  class  all  cotyledons  as  leaves  in  their  nature,  even  if  they 
are  quite  unable  to  do  the  ordinary  work  of  leaves.  The 
study  of  the  various  forms  which  the  parts  or  organs  of  a 
plant  may  assume  is  called  morphology  ;  it  traces  the  rela- 
tionship of  parts  which  are  really  akin  to  each  other, 
though  dissimilar  in  appearance  and  -often  in  function. 
In  seeds  which  have  endosperm,  or  food  stored  outside  of 
the  embryo,  the  cotyledons  usually  become  green  and 
leaf-like,  as  they  do,  for  example,  in  the  four-o'clock,  the 
morning-glory,  and  the  buckwheat ;  but  in  the  seeds  of 
the  grains  (which  contain  endosperm)  a  large  portion  of 
the  single  cotyledon  remains  throughout  as  a  thickish 
mass  buried  in  the  seed.  In  a  few  cases,  as  in  the  pea, 
there  are  scales  instead  of  true  leaves  formed  on  the  first 
nodes  above  the  cotyledons,  and  it  is  only  at  about  the 
third  node  above  that  leaves  of  the  ordinary  co 

kind  appear.  In  the  bean  and  some  other 
plants  which  in  general  bear  one  leaf  at  a 
node  along  the  stem,  there  is  a  pair  produced 
at  the  first  node  above  the  cotyledons,  and 
the  leaves  of  this  pair  differ  in  shape  from 
those  which  arise  from  the  succeeding  por- 
tions of  the  stem. 

45.    Classification  of  Plants  by  the  Number 
of  their  Cotyledons.  — In  the  pine  family  the     FlG  12  ^ 
germinating  seed  often  displays  more   than     minating  pine, 
two  cotyledons,  as  shown  in  Fig.  12;  in  the     co>  cotyledons- 
majority   of    common    flowering    plants    the    seed    con- 
tains two  cotyledons,  while  in  the  lilies,  the  rushes,  the 


V 


34 


FOUNDATIONS   OF  BOTANY 


sedges,  the  grasses,  and  some  other  plants,  there  is  but  one 
cotyledon.  Upon  these  facts  is  based  the  division  of  most 
flowering  plants  into  two  great  groups :  the  dicotyledonous 
plants,  which  have  two  seed-leaves,  and  the  monocotyledon- 
ous  plants,  which  have  one  seed-leaf.  Other  important 
differences  nearly  always  accompany  the  difference  in 
number  of  cotyledons,  as  will  be  seen  later. 

46.  Tabular  Review  of  Experiments.  —  Make  out  a 
table  containing  a  very  brief  summary  of  the  experiments 
thus  far  performed,  as  follows : 


NUMBER 
OF 

EXPERIMENT 

OBJECT 

SOUGHT 

MATERIALS 

AND 

APPARATUS 

OPERA- 
TIONS 
PERFORMED 

RESULTS 

INFERENCES 

47.  Review  Sketches.  —  Make  out  a  comparison  of  the 
early  life  histories  of  all  the  other  seedlings  studied,  by 
arranging  in  parallel  columns  a  series  of  drawings  of  each, 


MORPHOLOGY   OF   THE   SEEDLING 


35 


like  those  of  Fig.  9,  but  in  vertical  series,  the  youngest 
of  each  at  the  top,  thus  : 


BEAN 

PEA 

CORN 

FIRST  STAGE 

SECOND  STAGE 

THIRD  STAGE 

FOURTH  STAGE 

FIFTH  STAGE 

ETC. 

CHAPTER   IV 
•      ROOTS 1 

48.  Origin  of  Roots.  —  The  primary  root  originates  from 
the  lower  end  of  the  hypocotyl,  as  the  student  learned 
from   his    own    observations    on    sprouting    seeds.     The 
branches  of  the  primary  root  are  called  secondary  roots, 
and  the  branches  of   these    are  known   as  tertiary  roots. 
Those  roots  which  occur  on  the  stem  or  in  other  unusual 
places  are  known  as  adventitious  roots.     The  roots  which 
form   so  readily  on    cuttings    of   willow,   southernwood, 
tropseolum,    French    marigold,    geranium    (pelargonium), 
tradescantia,  and  many  other  plants,  when  placed  in  damp 
earth  or  water,  are  adventitious. 

49.  Aerial  Roots.  —While    the  roots  of  most  familiar 
plants  grow  in  the  earth  and  are  known  as  soil-roots,  there 
are  others  which  are  formed  in  the  air,  called  aerial  roots. 
They  serve  various  purposes :  in  some  tropical  air-plants 
(Fig.  13)  they  serve  to  fasten  the  plant  to  the  tree  on 
which  it  establishes  itself,  as  well  as  to  take  in  water  which 
drips  from  branches  and  trunks  above  them,  so  that  these 
plants  require  no  soil  and  grow  in  mid-air  suspended  from 
trees,  which  serve  them  merely  as  supports  ;  2   many  such 

1  To  the  plant  the  root  is  more  important  than  the  stem.    The  author  has, 
however,  treated  the  structure  of  the  latter  more  fully  than  that  of  the  root, 
mainly  because  the  tissues  are  more  varied  in  the  stem  and  a  moderate  knowl- 
edge of  the  more  complex  anatomy  of  the  stem  will  serve  every  purpose. 

2  If  it  can  be  conveniently  managed,  the  class  will  find  it  highly  interesting 
and  profitable  to  visit  any  greenhouse  of  considerable  size,  in  which  the  aerial 
roots  of  orchids  and  aroids  may  be  examined. 


ROOTS 


37 


air-plants  are  grown  in  greenhouses.  In  such  plants  as  the 
ivy  (Fig.  15)  the  aerial  roots  (which  are  also  adventitious) 
hold  the  plant  to  the  wall  or  other  surface  up  which  it  climbs. 
In  the  Indian  corn  (Fig.  14)  roots  are  sent  out  from 
nodes  at  some  dis- 

X7 

tance  above  the 
ground  and  finally 
descend  until  they 
enter  the  ground. 
They  serve  both  to 
anchor  the  cornstalk 
so  as  to  enable  it  to 
resist  the  wind  and 
to  supply  additional 
water  to  the  plant.1 
They  often  produce 
no  rootlets  until  they  (/ 
reach  the  ground. 

50.  Water-Roots.  — Many 
plants,  such  as  the  willow, 
readily  adapt  their  roots  to  j 
live  either  in  earth  or  in  water, 
and  some,  like  the  little  float- 
ing duckweed,  regularly  pro- 
duce roots  which  are  adapted  to  live  in  water 
only.  These  water-roots  often  show  large  and 
distinct  sheaths  on  the  ends  of  the  roots,  as,  for  instance, 
in  the  so-called  water-hyacinth.  This  plant  is  especially 
interesting  for  laboratory  cultivation  from  the  fact  that 


FlG.  13.  —  Aerial 
Boots  of  an  Orchid. 


1  Specimens  of  the  lower  part  of  the  cornstalk,  with  ordinary  roots  and 
aerial  roots,  should  be  dried  and  kept  for  class  study. 


38 


FOUNDATIONS  OF  BOTANY 


FlG.  14.— Lower  Part  of  Stem  and  Knots  of  Indian  Corn, showing  Aerial 
Roots  ( "  Brace-Roots  " ). 

a,  c,  internodes  of  the  stem  ;  b,  d,  e,f,  nodes  of  various  age  bearing  roots.    Most  of 
these  started  as  aerial  roots,  but  all  except  those  from  b  have  now  reached  the  earth. 


ROOTS 


39 


it  may  readily  be  transferred  to  moderately  damp  soil, 
and  that  the  whole  plant  presents  curious  modifications 
when  made  to  grow  in  earth  instead  of  water. 

51.  Parasitic  Roots.1  —  The  dodder,  the  mistletoe,  and  a 
good  many  other  parasites,  live  upon  nourishment  which 
they  steal  from  other  plants,  called  hosts.  The  parasitic 


FIG.  15.  —  Aerial  Adventitious  Roots  of  the  Ivy. 

roots,  or  haustoria,  form  the  most  intimate  connections 
with  the  interior  portions  of  the  stem  or  the  root,  as  the 
case  may  be,  of  the  host-plant  on  which  the  parasite 
fastens  itself. 

In  the  dodder,  as  is  shown  in  Fig.  16,  it  is  most  inter- 
esting to  notice  how  admirably  the  seedling  parasite  is 
adapted  to  the  conditions  under  which  it  is  to  live.  Rooted 

1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  pp.  171-213, 


40 


FOUNDATIONS   OF   BOTANY 


at  first  in  the  ground,  it  develops  a  slender,  leafless  stem, 
which,  leaning  this  way  and  that,  no  sooner  comes  into 


ABC 

FIG.  16.  —  Dodder,  growing  upon  a  Golden-Rod  Stem. 

s,  seedling  dodder  plants,  growing  in  earth  ;  h,  stem  of  host ;  r,  haustoria  or 
parasitic  roots  of  dodder  ;  Z,  scale-like  leaves.  A,  magnified  section  of  a  por- 
tion of  willow  stem,  showing  penetration  of  haustoria. 

permanent  contact  with  a  congenial  host  than  it  produces 
haustoria  at  many  points,  gives  up  further  growth  in  its 


ROOTS 


41 


soil-roots,  and  grows  rapidly  on  the  strength  of  the  sup- 
plies of  ready-made  sap  which  it  obtains  from  the  host. 

52.  Forms  of  Roots The  primary  root  is  that  which 

proceeds  like  a  downward  prolongation  directly  from  the 
lower  end  of  the  hypocotyl.  In  many  cases  the  mature  root- 
system  of  the  plant  contains  one  main  root  much  larger 
than  any  of  its  branches.  This  is  called  a  taproot  (Fig.  17). 

Such  a  root,  if  much  thickened,  would  assume  the  form 


FIG.  17.  —  A  Taproot.         FIG.  18.  —  Fibrous  Roots.         FIG.  19.  —  Fascicled  Roots. 

shown  in  the  carrot,  parsnip,  beet,  turnip,  salsify,  or  radish, 
and  is  called  a  fleshy  root.  Some  plants  produce  multiple 
primary  roots,  that  is,  a  cluster  proceeding  from  the  lower 
end  of  the  hypocotyl  at  the  outset.  If  such  roots  become 
thickened,  like  those  of  the  sweet  potato  and  the  dahlia 
(Fig.  19),  they  are  known  as  fascicled  roots. 

Roots  of  grasses,  etc.,  are  thread-like,  and  known  as 
fibrous  roots  (Fig.  18). 

53.  General  Structure  of  Roots The  structure  of  the 

very  young  root  can  be  partially  made  out  by  examining 


42 


FOUNDATIONS   OF   BOTANY 


the  entire  root  with  a  moderate  magnifying  power,  since 
the  whole  is  sufficiently  translucent  to  allow  the  interior 
as  well  as  the  exterior  portion  to  be  studied  while  the  root 
is  still  alive  and  growing. 

Place  some  vigorous  cuttings  of  tradescantia  or  Zebrina,  which' 
can  usually  be  obtained  of  a  gardener  or  florist,  in  a  beaker  or  jar  of 

water.1  The  jar  should 
be  as  thin  and  trans- 
parent as  possible,  and 
it  is  well  to  get  a  flat- 
sided  rather  than  a 
cylindrical  one.  Leave 
the  jar  of  cuttings  in 
a  sunny,  warm  place. 
As  soon  as  roots  have 
developed  at  the  nodes 
and  reached  the  length 
of  three-quarters  of  an 
inch  or  more,  arrange 
a  microscope  in  a  hori- 
zontal  position  (see 
Handbook),  and  exam- 
ine the  tip  and  adjacent 
portion  of  one  of  the 
young  roots  with  a 
power  of  from  twelve 
to  twent  diameters. 


FIG.  20.  —  Lengthwise    Section    (somewhat    diagram- 
matic) through  Root-Tip  of  Indian  Corn,    x  about  130. 

W,  root-cap  ;  i,  younger  part  of  cap  ;  z,  dead  cells  sepa- 
rating from  cap  ;  s,  growing  point ;  o,  epiderm's  ;  p', 
intermediate  layer  between  epidermis  and  central 
cylinder;  p,  central  cylinder;  d,  layer  from  which 
the  root-cap  originates. 


Note: 

(a)  The  root-cap, 

of    loosely 

attached  cells. 

(&)  The  central 

cylinder. 


1  If  the  tradescantia  or  Zebrina  cannot  be  obtained,  roots  of  seedlings  of 
oats,  wheat,  or  barley,  or  of  red-clover  seedlings  raised  in  a  large  covered  cell 
on  a  microscope  slide,  may  be  used. 


ROOTS  43 

(c)  The  cortical  portion,  a  tubular  part  enclosing  the  solid 
central  cylinder. 

(W)  The  root-hairs,  which  cover  some  parts  of  the  outer  layer  of 
the  cortical  portion  very  thickly.  Observe  particularly 
how  far  toward  the  tip  of  the  root  the  root-hairs  extend, 
and  where  the  youngest  ones  are  found. 

Make  a  drawing  to  illustrate  all  the  points  above  suggested 
(a,  6,  c,  rf).  Compare  your  drawing  with  Fig.  20.  Make  a  careful 
study  of  longitudinal  sections  through  the  centers  of  the  tips  of  very- 
young  roots  of  the  hyacinth  or  the  Chinese  sacred  lily.  Sketch 
one  section  and  compare  the  sketch  with  Fig.  20. 

Make  a  study  of  the  roots  of  any  of  the  common  duckweeds, 
growing  in  nutrient  solution  in  a  jar  of  water  under  a  bell-glass,  and 
note  the  curious  root-pockets  which  here  take  the  place  of  root-caps. 

54.  Details  of  Root-Structure.  —  The  plan  on  which  the 
young  root  is  built  has  been  outlined  in  Sect.  53.  A  few 
further  particulars  are  necessary  to  an  understanding  of 
how  the  root  does  its  work.  On  examining  Fig.  21  the 
cylinders  of  which  the  root  is  made  up  are  easily  dis- 
tinguished, and  the  main  constituent  parts  of  each  jean  be 
made  out  without  much  trouble.  The  epidermis-cells  are 
seen  to  be  somewhat  brick-shaped,  many  of  them  provided 
with  extensions  into  root-hairs.  Inside  the  epidermis  lie 
several  layers  of  rather  globular,  thin-walled  cells,  and 
inside  these  a  boundary  layer  between  the  cortical  or  bark 
portion  of  the  root  and  the  central  cylinder.  This  latter 
region  is  especially  marked  by  the  presence  of  certain 
groups  of  cells,  shown  at  w  and  d  and  at  £>,  the  two 
former  serving  as  channels  for  air  and  water,  the  latter 
(and  w  also)  giving  toughness  to  the  root. 

Roots  of  shrubs  and  trees  more  than  a  year  old  will 
be  found  to  have  increased  in  thickness  by  the  process 


44 


FOUNDATIONS   OF  BOTANY 


described  in  Sect.  106,  and  a  section  may  look  quite  unlike 
the  young  root-section  shown  in  Fig.  21. 

55,  Examination  of  the  Root  of  a  Shrub  or  Tree.  —  Cut  thin 
transverse  sections  of  large  and  small  roots  of  any  hardwood  tree  l 
and  examine  them  first  with  a  low  power  of  the  microscope,  as  a 
two-inch  objective,  to  get  the  general  disposition  of  the  parts,  then 

with  a  higher  power, 
as  the  half-inch  or 
quarter-inch,  for  de- 
tails. With  the  low 
power,  note : 

(a)  The  brown 
layer  of  outer  bark. 

(&)  The  paler  layer 
within  this. 

(c)  The  woody  cyl- 
inder which  forms 
the  central  portion  of 
the  root. 

The  distinction  be- 
tween (b)  and  (c)  is 
more  evident  when 
the  section  has  been 
exposed  to  the  air  for 
a  few  minutes  and 

h,  root-hairs  with  adhering  hits  of  sand  ;  e,  epidermis  ;    changed  somewhat  in 

color.  It  is  a  good 
plan  to  look  with  the 
low  power  first  at  a  thick  section,  viewed  as  an  opaque  object,  and 
then  at  a  very  thin  one  mounted  in  water  or  glycerine,  and  viewed  as 
a  transparent  object. 

Observe  the  cut-off  ends  of  the  ducts,  or  vessels,  which  serve  as 
passages  for  air  and  water  to  travel  through ;  these  appear  as  holes  in 
the  section,  and  are  much  more  abundant  relatively  in  the  young 

1  Young  suckers  of  cherry,  apple,  etc.,  which  may  be  pulled  up  by  the 
roots,  will  afford  excellent  material. 


FIG.  21.  —Much  Magnified  Cross-Section  of  a 
Very  Young  Dicotyledonous  Root. 


s,  thin-walled,  nearly  globular  cells  of  hark  ;  b,  hard 
bast ;  c,  cambium  ;  w,  wood-cells  ;  d,  ducts. 


ROOTS  45 

than  in  the  older  and  larger  portions  of  the  root.  Sketch  one  section 
of  each  kind. 

Examine  with  a  higher  power  (100  to  200  diameters),  and  note  the 
ends  of  the  thick-walled  wood-cells.  Compare  these  with  Fig.  72. 

Notice  the  many  thinner-walled  cells  composing  stripes  radiating 
away  from  the  center  of  the  root.  These  bands  are  the  medullary 
rays,  whose  mode  of  origin  is  shown  in  Fig.  68.  Moisten  some  of 
the  sections  with  iodine  solution,1  and  note  where  the  blue  color 
shows  the  presence  of  starch.  Split  some  portions  of  the  root  through 
the  middle,  cut  thin  sections  from  the  split  surface,  and  examine  with 
the  high  power  some  unstained  and  some  stained  with  iodine. 

Notice  the  appearance  of  the  wood-cells  and  the  ducts  as  seen  in 
these  sections,  and  compare  with  Fig.  58. 2 

56,  Structure  and  Contents  of  a  Fleshy  Root.  —  In  some 
fleshy  roots,  such  as  the  beet,  the  morphology  of  the  parts 
is  rather  puzzling,  since  they  form  man}*-  layers  of  tissue 
in  a  single  season,  showing  on  the  cross-section  of  the  root 
a  series  of  layers  which  look  a  little  like  the  annual  rings 
of  trees. 

The  structure  of  the  turnip,  radish,  carrot,  and  parsnip 
is  simpler. 

Cut  a  parsnip  across  a  good  deal  below  the  middle,  and  stand  the 
cut  end  in  eosin  solution  for  twTenty-four  hours. 

Then  examine  by  slicing  off  successive  portions  from  the  upper 
end.  Sketch  some  of  the  sections  thus  made.  Cut  one  parsnip 
lengthwise  and  sketch  the  section  obtained.  In  what  portion  of  the 
root  did  the  colored  liquid  rise  most  readily  ?  The  ring  of  red  marks 
the  boundary  between  the  cortical  portion  and  the  central  cylinder. 
To  which  does  the  main  bulk  of  the  parsnip  belong?  Cut  thin 
transverse  sections  from  an  ink-stained  parsnip  and  notice  how  the 
medullary  rays  run  out  into  the  cortical  portion,  and  in  those  sections 

1  If  the  roots  are  in  their  winter  condition. 

2  The  examination  of  the  minute  structure  of  the  root  is  purposely  made 
very  hasty,  since  the  detailed  study  of  the  structural  elements  can  be  made  to 
better  advantage  in  the  stem. 


46  FOUNDATIONS   OF  BOTANY 

that  show  it,  find  out  where  the  secondary  roots  arise.  If  possible, 
peel  off  the  cortical  portion  from  one  stained  root  and  leave  the  cen- 
tral cylinder  with  the  secondaiy  roots  attached.  Stain  one  section 
with  iodine,  and  sketch  it.  Where  is  the  starch  of  this  root  mainly 
stored? 

Test  some  bits  of  parsnip  for  proteids,  by  boiling  them  for  a 
minute  or  two  with  strong  nitric  acid. 

What  kind  of  plant-food  does  the  taste  of  cooked  parsnips  show 
them  to  contain  ?  [On  no  account  taste  the  bits  which  have  been 
boiled  in  the  'poisonous  nitric  acid.] 

57.  Storage  in  Other  Roots.  —  The  parsnip  is  by  no 
means  a  remarkable  plant  in  its  capacity  for  root-storage. 
The  roots  of  the  yam  and  the  sweet  potato  contain  a  good 
deal  of  sugar  and  much  more  starch  than  is  found,  in  the 
parsnip.  Beet-roots  contain  so  much  sugar  that  a  large 
part  of  the  sugar  supply  of  Europe  and  an  increasing 
portion  of  our  own  supply  is  obtained  from  them.  Often- 
times the  bulk  of  a  fleshy  root  is  exceedingly  large  as 
compared  with  that  of  the  parts  of  the  plant  above 
ground. 

The  South  African  plant  (Harpagophytum,  Chapter 
XXIV)  is  a  good  example  of  this,  and  another  instance 
is  that  of  a  plant,1  related  to  the  morning-glory  and  the 
sweet  potato,  found  in  the  southeastern  United  States, 
which  has  a  root  of  forty  or  fifty  pounds  weight. 

Not  infrequently  roots  have  a  bitter  or  nauseous  taste, 
as  in  the  case  of  the  chicory,  the  dandelion,  and  the 
rhubarb,  and  a  good  many,  like  the  monkshood,  the  yellow 
jasmine,  and  the  pinkroot,  are  poisonous.  Can  you  give 
any  reason  why  the  plant  may  be  benefited  by  the  disgust- 
ing taste  or  poisonous  nature  of  its  roots  ?  \ 
1  Ipom&a  Jalapa, 


ROOTS 


47 


58.  Use  of  the   Food  stored  in  Fleshy  Roots.  —  The 
parsnip,  beet,  carrot,  and  turnip  are  biennial  plants ;  that 
is,  they  do  not  produce  seed  until  the  second  summer  or 
fall  after  they  are  planted. 

The  first  season's  work  consists  mainly  in  producing  the 
food  which  is  stored  in  the  roots.  To  such  storage  is 
due  their  characteristic  fleshy  appear- 
ance. If  this  root  is  planted  in  the 
following  spring,  it  feeds  the  rapidly 
growing  stem  which  proceeds  from  the 
bud  at  its  summit,  and  an  abundant 
crop  of  flowers  and  seed  soon  follows ; 
while  the  root,  if  examined  in  late  sum- 
mer, will  be  found  to  be  withered,  with 
its  store  of  reserve  material  quite  ex- 
hausted. 

The  roots  of  the  rhubarb  (Fig.  22), 
the  sweet  potato,  and  of  a  multitude  of 
other  perennials,  or  plants  which  live 
for  many  years,  contain  much  stored 
plant-food.  Many  such  plants  die  to 
the  ground  at  the  beginning  of  winter, 
and  in  spring  make  a  rapid  growth  from  the  materials  laid 
up  in  the  roots. 

59.  Extent  of  the  Root-System.  —  The  total  length  of 
the  roots  of  ordinary  plants  is  much  greater  than  is  usually 
supposed.     They  are  so  closely  packed  in  the  earth  that 
only  a  few  of  the  roots  are  seen  at  a  time  during  the 
process  of  transplanting,  and  when  a  plant  is  pulled  or  dug 
up  in  the  ordinary  way,  a  large  part  of  the  whole  mass  of 
roots  is  broken  off  and  left  behind.     A  few  plants  have 


FIG.  22.  — Fleshy  Koots 

of  Garden  Rhubarb. 

(About  one-fifteenth 

natural  size.) 


48  FOUNDATIONS   OF  BOTANY 

been  carefully  studied  to  ascertain  the  total  weight  and 
length  of  the  roots.  Those  of  winter  wheat  have  been 
found  to  extend  to  a  depth  of  seven  feet.  By  weighing 
the  whole  root-system  of  a  plant  and  then  weighing  a 
known  length  of  a  root  of  average  diameter,  the  total 
length  of  the  roots  may  be  estimated.  In  this  way  the 
roots  of  an  oat  plant  have  been  calculated  to  measure 
about  154  feet;  that  is,  all  the  roots,  if  cut  off  and  strung 
together  end  to  end,  would  reach  that  distance. 

Single  roots  of  large  trees  often  extend  horizontally  to 
great  distances,  but  it  is  not  often  possible  readily  to  trace 
the  entire  depth  to  which  they  extend.  One  of  the  most 
notable  examples  of  an  enormously  developed  root-system 
is  found  in  the  mesquite  of  the  far  Southwest  and  Mexico. 
When  this  plant  grows  as  a  shrub,  reaching  the  height, 
even  in  old  age,  of  only  two  or  three  feet,  it  is  because  the 
water  supply  in  the  soil  is  very  scanty.  In  such  cases 
the  roots  extend  down  to  a  depth  of  sixty  feet  or  more, 
until  they  reach  water,  and  the  Mexican  farmers  in  dig- 
ging wells  follow  these  roots  as  guides.  Where  water  is 
more  plenty,  the  mesquite  forms  a  good-sized  tree,  with 
much  less  remarkably  developed  roots. 

60.  The  Absorbing  Surface  of  Roots. —  Such  aerial  roots 
as  are  shown  in  Fig.  13  are  usually  covered  with  a  spongy 
absorbent  layer,  by  means  of  which  they  retain  large 
quantities  of  the  water  which  trickles  down  them  during 
rain-storms.  This  water  they  afterwards  gradually  give 
up  to  the  plant.  Most  water-roots  (not  however  those  of 
tradescantia)  have  no  special  arrangement  for  absorbing 
water  except  through  the  general  surface  of  their  epidermis. 
But  some  water-roots  and  most  soil-roots  take  in  water 


ROOTS 


49 


mainly  through  the  root-hairs.  These  are  delicate,  hair- 
like  outgrowths  from  the  epidermis  of  the  root.  They 
are,  as  seen  in  Fig.  11,  thin-walled  tubes,  of  nearly  uniform 
diameter,  closed  at  the  outer  end  and  opening  at  the  inner 
end  into  the  epidermis-cell  from  which  they 
spring.  The  relation  of  each  hair  to  the 
epidermis-cell  is  still  better  shown  in  Fig. 
23,  which  represents  a  very  young  root- 
hair  and  a  considerably  older  one. 

61.  Absorption  of  Water  by  Roots.  — 
Many  experiments  on  the 
cultivation  of  corn,  wheat, 
oats,  beans,  peas,  and  other 
familiar  plants  in  water  have 
proved  that  some  plants,  at 
any  rate,  can  thrive  very 
well  on  ordinary  lake,  river, 
or  well  water,  together  with 
the  food  which  they  absorb 
from  the  air  (Chapter  XII). 
Just  how  much  water  some 
kinds  of  plants  give  off  (and 
therefore  absorb)  per  day 
will  be  discussed  when  the 
uses  of  the  leaf  are  studied. 
For  the  present  it  is  suffi- 
cient to  state  that  even  an 
annual  plant  during  its'  lifetime  absorbs  through  the  roots 
very  many  times  its  own  weight  of  water.  Grasses  have  been 
known  to  take  in  their  weight  of  water  in  every  twenty- 
four  hours  of  warm,  dry  weather.  This  absorption  takes 


n--- 


u 

B 


FIG.  23. 


A,  a  very  young  root-hair  ;  B,  a  much 
older  one  (both  greatly  magnified). 
e,  cells  of  the  epidermis  of  the  root ; 
n,  nucleus ;  s,  watery  cell-sap ;  p, 
thicker  protoplasm,  lining  the  cell- 
wall. 


50  FOUNDATIONS   OF  BOTANY 

place  mainly  through  the  root-hairs,  which  the  student  has 
examined  as  they  occur  in  the  seedling  plant,  and  which 
are  found  thickly  clothing  the  younger  and  more  rapidly 
growing  parts  of  the  roots  of  mature  plants.  Some  idea 
of  their  abundance  may  be  gathered  from  the  fact  that  on 
a  rootlet  of  corn  grown  in  a  damp  atmosphere,  and  about 
one-seventeenth  of  an  inch  in  diameter,  480  root-hairs  have 
been  counted  on  each  hundredth  of  an  inch  of  root.  The 
walls  of  the  root-hairs  are  extremely  thin,  and  they  have 
no  holes  or  pores  visible  under  even  the  highest  power 
of  the  microscope,  yet  the  water  of  the  soil  penetrates 
very  rapidly  to  the  interior  of  the  root-hairs.  The 
soil-water  brings  with  it  all  the  substances  which  it  can 
dissolve  from  the  earth  about  the  plant ;  and  the  close- 
ness with  which  the  root-hairs  cling  to  the  particles  of  soil, 
as  shown  in  Figs.  11  and  21,  must  cause  the  water  which 
is  absorbed  to  contain  more  foreign  matter  than  under- 
ground water  in  general  does,  particularly  since  the  roots 
give  off  enough  weak  acid  from  their  surface  to  corrode 
the  surface  of  stones  which  they  enfold  or  cover. 

62.  Osmosis.  —  The  process  by  which  two  liquids  sep- 
arated by  membranes  pass  through  the  latter  and  mingle, 
as  soil-water  does  with  the  liquid  contents  of  root-hairs,  is 
called  osmosis. 

It  is  readily  demonstrated  by  experiments  with  thin 
animal  or  vegetable  membranes. 

EXPERIMENT   XV 

Osmosis  as  shown  in  an  Egg.  —  Cement  to  the  smaller  end  of  an  egg 
a  bit  of  glass  tubing  about  six  inches  long  and  about  three-sixteenths 
of  an  inch  inside  diameter.  Sealing-wax  or  a  mixture  of  equal  parts 
of  beeswax  and  resin  melted  together  will  serve  for  a  cement. 


ROOTS 


51 


Chip  away  part  of  the  shell  from  the  larger  end  of  the  egg,  place 
it  in  a  wide-mouthed  bottle  or  a  small  beaker  full  of  water,  as  shown 
in  Fig.  24,  then  very  cautiously  pierce  a*  hole  through  the  upper  end 
of  the  eggshell  by  pushing  a  knitting-needle  or  wire  down  through 
the  glass  tube. 

Watch  the  apparatus  for  some  hours  and  note  any  change  in  the 
contents  of  the  tube.1  Explain. 

The  rise  of  liquid  in  the  tube  is  evidently  due  to  water  making 
its  way  through  the  thin  membrane  which  lines  the  eggshell, 
although  this  membrane  contains  no  pores  visible  even  under  the 
microscope. 

EXPERIMENT   XYI 

Result  of  placing  Sugar  on  a  Begonia  Leaf.  —  Place  a  little  pow- 
dered sugar  on  the  upper  surface  of  a  thick  begonia  leaf  under  a  small 
bell-glass.  Put  another  por- 
tion of  sugar  or  a  bit  of  paper 
alongside  the  leaf.  Watch  for 
several  days.  Explain  results. 
The  upper  surface  of  this  leaf 
contains  no  pores,  even  of 
microscopic  size. 

63.  Inequality  of  Os- 
motic Exchange.  —  The 
nature  of  the  two  liquids 
separated  by  any  given 
membrane  determines  in 
which  direction  the 
greater  flow  shall  take 
place. 

If  one  of  the  liquids  is 
pure  water  and  the  other 


FIG.  24.  —Egg  on  Beaker  of  Water, 
to  show  Osmosis. 


1  Testing  the  contents  of  the  beaker  with  nitrate  of  silver  solution  will 
then  show  the  presence  of  more  common  salt  than  is  found  in  ordinary  water. 
Explain. 


52  FOUNDATIONS   OF   BOTANY 

is  water  containing  solid  substances  dissolved  in  it,  the 
greater  flow  of  liquid  will  be  away  from  the  pure  water 
into  the  solution,  and  the  stronger  or  denser  the  latter,  the 
more  unequal  will  be  the  flow.  This  principle  is  well  illus- 
trated by  the  egg-osmosis  experiment.  Another  important 
principle  is  that  substances  which  readily  crystallize  and 
are  easily  soluble,  like  salt  or  sugar,  pass  rapidly  through 
membranes,  while  jelly-like  substances,  like  white  of  egg, 
can  hardly  pass  through  them  at  all. 

64.  Study  of  Osmotic  Action  of  Living  Protoplasm; 
Plasmolysis.  —  The  obvious  parts  of  most  living  and  grow- 
ing plant-cells  are  a  cell-wall,  which  is  a  skin  or  enclosure 
made  of  cellulose,  and  the  living,  active  cell-contents  or 
protoplasm.  Every  one  is  familiar  with  cellulose  in  vari- 
ous forms,  one  of  the  best  examples  being  that  afforded  by 
clean  cotton.  It  is  a  tough,  white  or  colorless  substance, 
chemically  rather  inactive.  Protoplasm  is  a  substance  which 
differs  greatly  in  its  appearance  and  properties  under  differ- 
ent circumstances.  It  is  of  a  very  complex  nature,  so  far  as 
its  chemical  composition  is  concerned,  belonging  to  the  group 
of  proteids  and  therefore  containing  not  only  the  elements 
carbon,  hydrogen,  and  oxygen,  common  to  most  organic 
substances,  but  nitrogen  in  addition.  The  protoplasm  in 
a  living  cell  often  consists  of  several  kinds  of  material ;  for 
instance,  a  rather  opaque  portion  called  the  nucleus,  and  a 
more  or  less  liquid  portion  lining  the  cell-walls  and  extend- 
ing inward  in  strands  to  the  nucleus  (Fig.  126).  Often,  in 
living  and  active  cells,  the  spaces  left  between  strands  and 
lining  are  filled  with  a  watery  liquid  called  the  cell-sap. 

The  action  of  the  protoplasm  in  controlling  osmosis  is 
well  shown  by  the  process  known  as  plasmolysis. 


ROOTS  53 

Put  some  living  threads  of  pond-scum  (Spirogyra)  (Chapter  XX) 
into  a  4  per  cent  solution  of  glycerine  in  water,  a  16  per  cent  solution 
of  cane  sugar,  or  (for  quick  results)  a  2  per  cent  solution  of  common 
salt.1  Any  one  of  these  solutions  is  much  denser  than  the  cell-sap 
inside  the  cells  of  the  pond-scum,  and  therefore  the  watery  part  of 
the  cell-contents  will  be  drawn  out  of  the  interior  of  the  cell  and 
the  protoplasmic  lining  will  collapse,  receding  from  the  cell-wall. 
The  cell-contents  are  then  said  to  be  plasmolyzed.  Sketch  several 
cells  in  this  condition.  Remove  the  filaments  of  Spirogyra  and 
place  them  in  fresh  water.  How  do  they  now  behave  ?  Explain. 
Repeat  the  plasmolyzing  operation  with  another  set  of  cells  which 
have  first  been  killed  by  soaking  them  for  five  minutes  in  a  mixture 
of  equal  quantities  of  acetic  acid,  three  parts  to  1000  of  water,  and 
chromic  acid,  seven  parts  to  1000  of  water.  The  pond-scum  threads 
before  being  transferred  from  the  killing  solution  into  the  plas- 
molyzing solution  should  be  rinsed  with  a  little  clear  water.  Note 
how  the  cells  now  behave.  How  is  it  shown  that  they  have  lost 
their  power  of  causing  a  liquid  to  be  transferred  mainly  or  wholly 
in  one  direction?  Why  do  frozen  or  boiled  slices  of  a  red  beet 
color  water  in  which  they  are  placed,  while  fresh  slices  do  not? 

65.  Osmosis  in  Root-Hairs.  —  The  soil-water  (practically 
identical  with  ordinary  spring  or  well  water)  is  separated 
from  the  more  or  less  sugary  or  mucilaginous  sap  inside 
of  the  root-hairs  only  by  their  delicate  cell-walls,  lined 
with  a  thin  layer  of  protoplasm.  This  soil- water  will  pass 
rapidly  into  the  plant,  while  very  little  of  the  sap  will 
come  out.  The  selective  action,  which  causes  the  flow  of 
liquid  through  the  root-hairs  to  be  almost  wholly  inward, 
is  due  to  the  living  layer  of  protoplasm  (Chapter  XII), 
which  covers  the  inner  surface  of  the  cell-wall  of  the  root- 
hair.  When  the  student  has  learned  how  active  a  sub- 
stance protoplasm  often  shows  itself  to  be,  he  will  not  be 
astonished  to  find  it  behaving  almost  as  though  it  were 

1  This  should  be  done  as  a  demonstration  by  the  teacher. 


54  FOUNDATIONS   OF   BOTANY 

possessed  of  intelligence  and  will.  Plants  of  two  different 
species,  both  growing  in  the  same  soil,  usually  take  from 
it  very  various  amounts  or  kinds  of  mineral  matter.  For 
instance,  barley  plants  in  flower  and  red-clover  plants  in 
flower  contain  about  the  same  proportion  of  mineral  mat- 
ter (left  as  ashes  after  burning).  But  the  clover  contains 
5|  times  as  much  lime  as  the  barley,  and  the  latter  contains 
about  eighteen  times  as  much  silica  as  the  clover.  This 
difference  must  be  due  to  the  selective  action  of  the  proto- 
plasm in  the  absorbing  cells  of  the  roots.  Traveling  by 
osmotic  action  from  cell  to  cell,  a  current  of  water  derived 
from  the  root-hairs  is  forced  up  through  the  roots  and  into 
the  stem,  just  as  the  contents  of  the  egg  was  forced  up 
into  the  tube  shown  in  Fig.  24. 

66.  Root-Pressure.  —  The  force  with  which  the  upward- 
flowing  current  of  water  presses  may  be  estimated  by 
attaching  a  mercury  gauge  to  the  root  of  a  tree  or  the 
stem  of  a  small  sapling.  This  is  best  done  in  early  spring 
after  the  thawing  of  the  ground,  but  before  the  leaves 
have  appeared.  The  experiment  may  also  be  performed 
indoors  upon  almost  any  plant  with  a  moderately  firm 
stem,  through  which  the  water  from  the  soil  rises  freely. 
A  dahlia  plant  or  a  tomato  plant  answers  well,  though  the 
root-pressure  from  one  of  these  will  not  be  nearly  as  great 
as  that  from  a  larger  shrub  or  a  tree  growing  out  of  doors. 
In  Fig.  25  the  apparatus  is  shown  attached  to  the  stem  of 
a  dahlia.  The  difference  of  level  of  the  mercury  in  the 
bent  tube  serves  to  measure  the  root-pressure.  For  every 
foot  of  difference  in  level  there  must  be  a  pressure  of 
nearly  six  pounds  per  square  inch  on  the  stump  at  the 
base  of  the  tube  T.1 

1  See  Handbook, 


ROOTS 


55 


A  black-birch  root  tested  in  this  way  at  the  end  of 
April  has  given  a  root-pressure  of  thiity-seven  pounds  to 
the  square  inch.  This  would  sustain  a  column  of  water 
about  eighty-six  feet  high. 

67.  Root-Absorption  and 
Temperature  of  Soil.  —  It 
would  not  be  remarkable  if 
the  temperature  of  roots  and 
the  earth  about  them  had 
something  to  do  with  the 
rate  at  which  they  absorb 
water,  since  this  absorption 
depends  on  the  living  proto- 
plasm of  the  root-hairs  (see 
Sects.  64,  65).  An  experi- 
ment will  serve  to  throw 
some  light  on  this  question. 


EXPERIMENT   XVII 

Effect  of  Temperature  on  Absorp- 
tion of  Water  by  Roots.  —  Trans- 

.  ...          i        ,  /?  T7,  large  tube  fastened  to  the  stump  of 

plant  a  tobacco  seedling  about  four       th    d  h]i     t      b          bb     t  b 


FIG.  25.  —  Apparatus  to  Measure 
Root-Pressure. 


rr,  rubber  stoppers;  t,  bent  tube 
containing  mercury  ;  1 1',  upper  and 
lower  level  of  mercury  in  T. 


inches  high  into  rich  earth  con- 
tained in  a  narrow,  tall  beaker  or 
very  large  test-tube  (not  less  than 
1£  inch  in  diameter  and  six  inches  high).  When  the  plant  has  begun 
to  grow  again  freely,  in  a  warm,  sunny  room,  insert  a  chemical  ther- 
mometer into  the  earth,  best  by  making  a  hole  with  a  sharp  round 
stick,  pushed  nearly  to  the  bottom  of  the  tube,  and  then  putting  the 
thermometer  in  the  place  of  the  stick.  Water  the  plant  well,  then 
set  the  tube  in  a  jar  of  pounded  ice  which  reaches  nearly  to  the 
top  of  the  tube.  Note  the  temperature  of  the  earth  just  before 
placing  it  in  the  ice.  Observe  whether  the  leaves  of  the  seedling  wilt, 


56  FOUNDATIONS   OF   BOTANY 

and,  if  so,  at  what  temperature  the  wilting  begins.  Finally,  remove 
the  tube  from  the  ice  and  place  it  in  warm  water  (about  80°). 
Observe  the  effect  and  note  the  temperature  at  which  the  plant, 
if  wilted,  begins  to  revive.  Find  an  average  between  the  wilting 
temperature  and  the  reviving  temperature.  For  what  does  this 
average  stand? 

68,  Movements  of  Young  Roots.  —  The  fact  that  roots 
usually  grow  downward  is  so  familiar  that  we  do  not 
generally  think  of  it  as  a  thing  that  needs  discussion  or 
explanation.  Since  they  are  pretty  flexible,  it  may  seem 
as  though  young  and  slender  roots  merely  hung  down 
by  their  own  weight,  like  so  many  bits  of  wet  cotton 
twine.  But  a  very  little  experimenting  will  answer  the 
question  whether  this  is  really  the  case. 

EXPERIMENT   XVIII 

Do  all  Parts  of  the  Root  of  the  Windsor  Bean  Seedling  bend  down- 
ward alike?  —  Fasten  some  sprouting  Windsor  beans  with  roots 
about  an  inch  in  length  to  the  edges  of  a  disk  of  pine  wood  or 
other  soft  wood  in  a  soup-plate  nearly  full  of  water  and  cover  them 
with  a  low  bell-jar.  Pins  run  through  the  cotyledons,  as  in  Fig.  26, 
will  hold  the  beans  in  place.  When  the  roots  have  begun  to  point 
downward  strongly,  turn  most  of  the  beans  upside  down  and  pin 
them  in  the  reversed  position.  If  you  choose,  after  a  few  days 
reverse  them  again.  Make  sketches  of  the  various  forms  that  the 
roots  assume  and  discuss  these. 

EXPERIMENT   XIX 

Does  the  Windsor  Bean  Root-Tip  press  downward  with  a  Force 
greater  than  its  Own  Weight  ?  —  Arrange  a  sprouted  bean  as  shown 
in  Fig.  26,  selecting  one  that  has  a  root  about  twice  as  long  as  the 
diameter  of  the  bean  and  that  has  grown  out  horizontally,  having 
been  sprouted  on  a  sheet  of  wet  blotting  paper.  The  bean  is  pinned 


ROOTS 


57 


FIG.  26.  —  A  Sprouting  "Windsor  Bean  pushing  its 
Root-Tip  into  Mercury. 

s,  seed  ;  r,  root ;  w,  layer  of  water  ;  m,  mercury. 


to  a  cork  that  is  fastened  with  beeswax  and  resin  mixture  to  the 
side  of  a  little  trough  or  pan  of  glass  or  glazed  earthenware.  The 
pan  is  filled  half  an  inch  or  more  with  mercury,  and  on  top  of 
the  mercury  is  a  layer 

of  water.     The  whole  f  ^^    \ 

is  closely  covered  by 
a  large  tumbler  or  a 
bell-glass.  Allow  the 
apparatus  to  stand  un- 
til the  root  has  forced 
its  way  down  into  the 
mercury.  Then  run  a 
slender  needle  into  the 
root  where  it  enters 
the  mercury  (to  mark 
the  exact  level),  withdraw  the  root,  and  measure  the  length  of 
the  part  submerged  in  mercury.  To  see  whether  this  part  would 
have  stayed  under  by  virtue  of  its  own  weight,  cut  it  off  and  lay 
it  on  the  mercury.  Push  it  under  with  a  pair  of  steel  forceps  and 
then  let  go  of  it.  What  does  it  do  ? 

69,  Discussion  of  Exp.  XIX.  —  By  comparing  the  weights 
of  equal  bulks  of  mercury  and  Windsor  bean  roots,  it  is 
found  that  the  mercury  is  about  fourteen  times  as  heavy 
as  the  substance  of  the  roots.     Evidently,  then,  the  sub- 
merged part  of  the  root  must  have  been  held  under  by 
a  force  about  fourteen  times  its  own  weight.     Making  fine 
equidistant  cross-marks  with  ink  along  the  upper  and  the 
lower  surface  of  a  root  that  is  about  to  bend  downward  at 
the  tip,  readily  shows  that  those  of  the  upper  series  soon 
come  to  be  farther  apart,  —  in  other  words,  that  the  root  is 
forced  to  bend  downward  by  the  more  rapid  growth  of  its 
upper  as  compared  with  its  under  surface. 

70.  Geotropism.  —  The  property  which  plants  or  their 
organs   manifest,   of   assuming  a  definite  direction  with 


58 


FOUNDATIONS   OF   BOTANY 


reference  to  gravity,1  is  called  geotropism.  When,  as  in 
the  case  of  the  primary  root,  the  effect  of  gravity  is  to 
make  the  part  if  unobstructed  turn  or  move  downward, 
we  say  that  the  geotropism  is  positive.  If  the  tendency  is 
to  produce  upward  movement,  we  say  that  the  geotropism 
is  negative;  if  horizontal  movement,  that  it  is  lateral.  It 
was  stated  in  the  preceding  section  that  the  direct  cause 
of  the  downward  extension  of  roots  is  unequal  growth. 
We  might  easily  suppose  that  this  unequal  growth  is  not 
due  to  gravity,  but  to  some  other  cause.  To  test  this  sup- 
position, the  simplest  plan  (if  it  could  be  carried  out)  would 
be  to  remove  the  plants  studied  to  some  distant  region 
where  gravity  does  not  exist.  This  of  course  cannot  be 

done,  but  we  can  easily  turn  a 
young  seedling  over  and  over 
so  that  gravity  will  act  on  it 
now  in  one  direction,  now  in 
another,  and  so  leave  no  more 
impression  than  if  it  did  not  act 
at  all  (Exp.  XX).  Or  we  can 
whirl  a  plant  so  fast  that  not 
only  is  gravity  done  away  with, 
but  another  force  is  introduced 
in  its  place.  If  a  vertical  wheel, 
like  a  carriage  wheel,  were  pro- 
vided with  a  few  loosely  fitting 
iron  rings  strung  on  the  spokes, 
when  the  wheel  was  revolved  rapidly  the  rings  would  all 
fly  out  to  the  rim  of  the  wheel.  So  in  Fig.  27  it  will  be 


FIG.  27.— Sprouting  Peas,  on  the  Disk 
of  a  rapidly  Whirling  Clinostat. 

The  youngest  portions  of  the  roots 
all  point  directly  away  from  the 
axis  about  which  they  were  re- 
volved. 


1  Gravity  means  the  pull  which  the  earth  exerts  upon  all  objects  on  or 
near  its  surface. 


ROOTS  59 

noticed  that  the  growing  tips  of  the  roots  of  the  sprouting 
peas  point  almost  directly  outward  from  the  center  of  the 
disk  on  which  the  seedlings  are  fastened.  Explain  the  differ- 
ence between  this  result  and  that  obtained  in  Exp.  XX. 

S^        r* 

-, 

EXPERIMENT   XX 

How  do  Primary  Roots  point  when  uninfluenced  by  Gravity  ?  Pin 
some  soaked  Windsor  beans  to  a  large  flat  cork,  cover  them  with 
thoroughly  moistened  chopped  peat-moss,  and  cover  this  with  a  thin 
glass  crystallizing  dish.  Set  the  cork  on  edge.  Prepare  another 
cork  in  the  same  way,  attach  it  to  a  clinostat,  and  keep  it  slowly 
revolving  in  a  vertical  position  for  from  three  to  five  days.  Com- 
pare the  directions  taken  by  the  roots  on  the  stationary  and  on  the 
revolving  cork.1 

71.  Direction  taken  by  Secondary  Roots.  —  As  the  stu- 
dent has  already  noticed  in  the  seedlings  which  he  has 
studied,  the  branches  of  the  primary  root  usually  make  a 
considerable  angle  with  it  (Fig.  2).     Often  they  ran  out 
for  long  distances  almost  horizontally.     This  is  especially 
common  in  the  roots  of  forest  trees,  above  all  in  cone- 
bearing  trees,  such  as  pines  and  hemlocks.     This  horizon- 
tal or  nearly  horizontal  position  of  large  secondary  roots 
is  the  most  advantageous  arrangement  to  make  them  use- 
ful in  staying  or  guying  the  stem  above,  to  prevent  it  from 
being  blown  over  by  the  wind. 

72.  Fitness  of  the  Root  for  its  Position  and  Work.  —  The 
distribution  of  material  in  the  woody  roots  of  trees  and 
shrubs  and  their  behavior  in  the  soil  show  many  adapta- 
tions to  the  conditions  by  which  the  roots  are  surrounded. 

1  See  Ganong's  Teaching  Botanist,  pp.  182-186,  for  complete  directions. 
The  brief  statement  above  given  is  abstracted  from  that  of  Professor  Ganong. 


60 


FOUNDATIONS   OF  BOTANY 


The  growing  tip  of  the  root,  as  it  pushes  its  way  through 
the  soil,  is  exposed  to  bruises  ;  but  these  are  largely  warded 
off  by  the  root-cap.  The  tip  also  shows  a  remarkable 
sensitiveness  to  contact  with  hard  objects,  so  that  when 
touched  by  one  it  swerves  aside  and  thus  finds  its  way 
downward  by  the  easiest  path.  Roots  with  an  unequal 
water  supply  on  either  side  grow  toward  the  moister  soil. 
Roots  are  very  tough,  because  they  need  to  resist  strong 


FIG.  28.  —  Roots  of  a  Western  Hemlock  exposed  by  having  most  of  the  Leaf -Mould 
about  them  burned  away  by  Forest  Fires. 

pulls,  but  not  as  stiff  as  stems  and  branches  of  the  same 
size,  because  they  do  not  need  to  withstand  sidewise  pres- 
sure, acting  from  one  side  only.  The  corky  layer  which 
covers  the  outsides  of  -roots  is  remarkable  for  its  power 
of  preventing  evaporation.  It  must  be  of  use  in  retaining 
in  the  root  the  moisture  which  otherwise  might  be  lost 
on  its  way  from  the  deeper  rootlets  (which  are  buried  in 
damp  soil),  through  the  upper  portions  of  the  root-system, 
about  which  the  soil  is  often  very  dry. 


ROOTS  61 

73,  Propagation  by  Means  of   Roots.  —  Some   familiar 
plants,  such  as  rose  bushes,  are  usually  grown  from  roots 
or  root-cuttings. 

Bury  a  sweet  potato  or  a  dahlia  root  in  damp  sand,  and  watch 
the  development  of  sprouts  from  adventitious  buds.  One  sweet 
potato  will  produce  several  such  crops  of  sprouts,  and  every  sprout 
may  be  made  to  grow  into  a  new  plant.  It  is  in  this  way  that  the 
crop  is  started  wherever  the  sweet  potato  is  grown  for  the  market. 

74,  Tabular  Review  of  Experiments. 
[Continue  the  table  begun  at  end  of  Chapter  III.] 

75,  Review  Summary  of  Roots. 

Kinds  of  roots  as  regards  origin      .     .     .     .     . 

Kinds  as  regards  medium  in  which  they  grow  . 

Structure  of  root  of  a  tree. 

T  mate  rials. 
Storage  in  roots *{  location. 

louses. 

f  apparatus. 

amount. 

Absorption  of  water  by  roots ^ 

I  proofs. 

^causes. 

f  nature. 
Movements  of  roots J  causes. 

I  uses. 


CHAPTER   Y 
STEMS 

76.  What  the  Stem  is The  work  of  taking  in  the  raw 

materials  which  the  plant  makes  into  its  own  food  is  done 
mainly  by  the  roots  and  the  leaves.      These  raw  materials 
are  taken  from  earth,  from  water,  and  from  the  air  (see 
Chapter  XI).     The  stern  is  that  part  or  organ  of  the  plant 
which  serves  to  bring  roots  and  leaves  into  communication 
with  each  other.     In  most  flowering  plants  the  stem  also 
serves  the  important  purpose  of  lifting  the  leaves  up  into 
the  sunlight,  where  alone  they  best  can  do  their  special 
work. 

The  student  has  already,  in  Chapter  III,  learned  some- 
thing of  the  development  of  the  stem  and  the  seedling  ; 
he  has  now  to  study  the  external  appearance  and  internal 
structure  of  the  mature  stem.  Much  in  regard  to  this 
structure  can  conveniently  be  learned  from  the  examina- 
tion of  twigs  and  branches  of  our  common  forest  trees  in 
their  winter  condition. 

77.  The  Horse-Chestnut  Twig.1  —  Procure  a  twig  of  horse-chest- 
nut eighteen  inches  or  more  in  length.    Make  a  careful  sketch  of  it, 
trying  to  bring  out  the  following  points : 

(1)  The  general  character  of  the  bark. 

1  Where  the  buckeye  is  more  readily  obtained  it  will  do  very  well.  Hick- 
ory twigs  answer  the  same  purpose,  and  the  latter  is  a  more  typical  form, 
having  alternate  buds.  The  magnolia  or  the  tulip  tree  will  do.  The  student 
should  (sooner  or  later)  examine  at  least  one  opposite-  and  one  alternate-leaved 
twig. 

62 


STEMS 


63 


(2)  The  large  horseshoe-shaped  scars  and  the  number  and  posi- 
tion of  the  dots  on  these  scars.     Compare  a  scar  with  the  base  of  a 
leaf-stalk  furnished  by  the  teacher. 

(3)  The  ring  of  narrow  scars  around  the  stem  in  one  or  more 
places,1  and  the  different  appearance  of  the  bark  above  and  below 
such  a  ring.     Compare  these  scars  with  those  left  after  removing  the 
scales  of  a  terminal  bud  and  then  see  Fig.  29,  b  sc. 

(4)  The  buds  at  the  upper  margin  of  each  leaf- 
scar  and  the  strong  terminal  bud  at  the  end  of  the 
twig. 

(5)  The  flower-bud  scar,  a  concave  impression, 
to  be  found  in  the  angle  produced  by  the  forking 
of  two  twigs,  which  form,  with  the  branch  from 
which  they  spring,  a  Y-shaped  figure  (see  Fig.  36). 

(6)  (On  a  branch  larger  than  the  twig  handed 
round  for  individual  study)  the  place  of  origin  of 
the  twigs  on  the  branch  ;  —  make  a  separate  sketch 
of  this. 

The  portion  of  stem  which  originally  bore  any 
pair  of  leaves  is  called  a  node,  and  the  portions  of 
stem  between  nodes  are  called  internodes. 

Describe  briefly  in  writing  alongside  the  sketches 
any  observed  facts  which  the  drawings  do  not  show. 

If  your  twig  was  a  crooked,  rough-barked,  and 
slow-growing  one,  exchange  it  for  a  smooth,  vig- 
orous one,  and  note  the  differences.  Or  if  you 
sketched  a  quickly  grown  shoot,  exchange  for  one 
of  the  other  kind. 

Answer  the  following  questions  :  6  sc  bud-scale  scars. 

(a)  How   many  inches    did    your    twig    grow    A11    above    these 
-,  ,  ,       ,  scars  is  the  growth 
during  the  last  summer?  of  the  spri*g  and 

How  many  in  the  summer  before?  summer  of  the 

How  do  you  know? 

How  many  years  old  is  the  whole  twig  given  you  ? 

(b)  How  were  the  leaves  arranged  on  the  twig? 


..b  sc 


Cherry,  with  Lat- 
eral and  Terminal 
Buds  in  October. 


same  year. 


1  A  very  vigorous  shoot  may  not  show  any  such  ring. 


64  FOUNDATIONS   OF   BOTANY 

How  many  leaves  were  there  ? 
Were  they  all  of  the  same  size  ? 

(c)  What  has  the  mode  of  branching  to  do  with  the  arrangement 
of  the  leaves  ?  with  the  flower-bud  scars  ? 

(d)  The  dots  on  the  leaf-scars  mark  the  position  of  the  bundles 
of  ducts  and  wood-cells  which  run  from  the  wood  of  the  branch 
through  the  leaf -stalk  up  into  the  leaf. 

78.  Twig  of  Beech.  —  Sketch  a  vigorous  young  twig  of  beech  (or 
of  hickory,  magnolia,  tulip  tree)  in  its  winter  condition,  noting  par- 
ticularly the  respects  in  which  it  differs  from  the  horse-chestnut. 
Describe  in  writing  any  facts  not  shown  in  the  sketch.     Notice  that 
the  buds  are  not  opposite,  nor  is  the  next  one  above  any  given  bud 
found  directly  above  it,  but  part  way  round  the  stem  from  the  posi- 
tion of  the  first  one.      Ascertain,  by  studying  several  twigs  and 
counting  around,  which  bud  is  above  the  first  and  how  many  turns 
round  the  stem  are  made  in  passing  from  the  first  to  the  one  directly 
above  it. 

Observe  with  especial  care  the  difference  between  the  beech  and 
the  horse-chestnut  in  mode  of  branching,  as  shown  in  a  large  branch 
provided  for  the  study  of  this  feature. 

79.  Relation  of  Leaf -Arrangement  to  Branching.1  —  This 
difference,  referred  to  in  Sect.  78,  depends  on  the  fact  that 
the  leaves  of  the  horse-chestnut  were  arranged  in  pairs,  on 
opposite  sides  of  the  stem,  while  those  of  the  beech  were 
not  in  pairs.     Since  the  buds  are  found  at  the  upper  edges 
of  the  leaf-scars,  and  since  most  of  the  buds  of  the  horse- 
chestnut  and  the  beech  are  leaf-buds  and  destined  to  form 
branches,  the  mode  of  branching  and  ultimately  the  form 

1  The  teacher  in  the  Eastern  and  Middle  States  will  do  well  to  make  constant 
use,  in  the  study  of  branches  and  buds,  of  Miss  Newell's  Outlines  of  Lessons 
in  Botany,  Part  I.  The  student  can  observe  for  himself,  with  a  little  guid- 
ance from  the  teacher,  most  of  the  points  which  Miss  Newell  suggests.  If  the 
supply  of  material  is  abundant,  the  twigs  employed  in  the  lessons  above 
described  need  not  be  used  further,  but  if  material  is  scanty,  the  study  of  buds 
may  at  once  be  taken  up.  (See  also  Bailey's  Lessons  with  Plants,  Part  I.) 


STEMS 


65 


of  the  tree  must  depend  largely  on  the  arrangement  of 

leaves  along  the  stem. 

80.    Opposite  Branching In  trees  the  leaves  and  buds 

of  which  are  opposite,  the  tendency  will  be  to  form  twigs 

in  four  rows  about  at  right  angles 

to  each  other  along  the  sides  of 

the  branch,  as  shown  in  Fig.  30. 

This  arrangement  will  not  usu- 
ally be  perfectly  carried  out,  since 

some  of  the  buds  may  never  grow, 
or  some  may 
grow  much 
faster  than 
others  and  so 
make  the  plan 
of  branching  less 
evident  than  it 
would  be  if  all 
grew  alike. 

81.    Alternate 
Branching. — In 

trees  like  the  beech  the  twigs  will  be 
found  to  be  arranged  in  a  more  or  less 
regular  spiral  line  about  the  branch. 
This,  which  is  known  as  the  alternate 
arrangement  (Fig.  31),  is  more  com- 
monly met  with  in  trees  and  shrubs 
than  the  opposite  arrangement.  It  ad- 
mits of  many  varieties,  since  the  spiral 

may  wind  more  or  less  rapidly  round  the  stem.     In  the 

apple,  pear,  cherry,  poplar,  oak,  and  walnut,  one  passes 


FIG.  30.  —  Opposite  Branching 

in  a  very  Young  Sapling 

of  Ash. 


FIG.  31.  — Alternate 
Branching  in  a  very 
Young  Apple  Tree. 


66 


FOUNDATIONS   OF   BOTANY 


FIG.  32.  —  Excurrent  Trunks  of  Big  Trees 
(Sequoias). 


over  five  spaces  before 
coming  to  a  leaf  which 
is  over  the  first,  and  in 
doing  this  it  is  necessary 
to  make  two  complete 
turns  round  the  stem 
(Fig.  105). 

82.  Growth  of  the  Ter- 
minal Bud.  —  In  some 
trees  the  terminal  bud 
from  the  very  outset 
keeps  the  leading  place, 
and  the  result  of  this 
mode  of  growth  is  to 
produce  a_slender,  up- 
right tree,  with  an  excur- 
rent  trunk  like  that  of 
Fig.  32. 

In  such  trees  as  the 
apple  and  many  oaks  the 
terminal  bud  has  no  pre- 
eminence over  others,  and 
the  form  of  the  tree  is 
round-topped  and  spread- 
ing, deliquescent  like  that 
in  Fig.  33. 

Most  of  the  larger  for- 
est trees  are  intermediate 
between  these  extremes. 

Branches  get  their 
characteristics  to  a 


STEMS 


67 


FIG.  33.  —  An  American  Elm,  with  Deliquescent  Trunk. 

considerable  degree  from  the  relative  importance  of  their 
terminal  buds.  If  these  are  mainly  flower-buds,  as  is  the  case 
in  the  horse-chestnut  and  some  magnolias  (Figs.  35,  36), 


68  FOUNDATIONS    OF   BOTANY 

the  tree  is  characterized  by  frequent  forking,  and  has 
no  long  horizontal  branches. 

If  the  terminal  bud  keeps  the  lead  of  the  lateral  ones, 
but  the  latter  are  numerous  and  most  of  them  grow  into 
slender  twigs,  the  delicate  spray  of  the  elm  and  many 
birches  is  produced  (Fig.  37). 

The  general  effect  of  the  branching  depends  much  upon 
the  angle  which  each  branch  or  twig  forms  with  that  one 
froni  which  it  springs.  The  angle  may  be  quite  acute,  as 
in  the  birch  ;  or  more  nearly  a  right  angle,  as  in  the  ash 
(Fig.  30).  The  inclination  of  lateral  branches  is  due  to 
geotropism,  just  as  is  that  of  the  branches  of  primary  roots. 
The  vertically  upward  direction  of  the  shoot  which  grows 
from  the  terminal  bud  is  also  due  to  geotropism. 

This  is  really  only  a  brief  way  of  sajdng  that  the  grow- 
ing tip  of  the  main  stem  of  the  tree  or  of  any  branch  is 
made  to  take  and  keep  its  proper  direction,  whether  verti- 
cally upward  or  at  whatever  angle  is  desirable  for  the  tree, 
by  the  steering  action  of  gravity.  After  growth  has  ceased 
this  steering  action  can  no  longer  be  exerted,  and  so  a  tree 
that  has  been  bent  over  (as,  for  instance,  by  a  heavy  load 
of  snow)  cannot  right  itself,  unless  it  is  elastic  enough  to 
spring  back  when  the  load  is  removed.  The  tip  of  the 
trunk  and  of  each  branch  can  grow  and  thus  become 
vertical,  but  the  old  wood  cannot  do  so. 

83.  Thorns  as  Branches.  —  In  many  trees  some  branches 
show  a  tendency  to  remain  dwarfish  and  incompletely 
developed.  Such  imperfect  branches  forming  thorns  are 
familiar  in  wild  crab-apple  trees  and  in  the  pear  trees 
which  occur  in  old  pastures  in  the  Northeastern  States.  In 
the  honey  locust  very  formidable  branching  spines  spring 


STEMS 


69 


from  adventitious  or  dormant  buds  on  the  trunk  or  limbs. 
Such  spines  sometimes  show  their  true  nature  as  branches 
by  bearing  leaves  (Fig.  34). 

84.  Indefinite  Annual  Growth.  —  In  most  of  the  forest 
trees,  and  in  the  larger  shrubs,  the  wood  of  young  branches 
is  matured  and  fully 

developed  during  the 
summer.  Protected 
buds  are  formed  on 
the  twigs  of  these 
branches  to  their  very 
tips.  In  other  shrubs 
—  for  example,  in  the 
sumac,  the  raspberry, 
and  blackberry  —  the 
shoots  continue  to 
grow  until  their  soft 
and  immature  tips  are 
killed  by  the  frost. 

Such  a  mode  of  growth  is  called  indefinite 
annual  growth,  to  distinguish  it  from  the 
definite  annual  growth  of  most  trees. 

85.  Trees,  Shrubs,  and  Herbs.  —  Plants 
of  the  largest  size  with  a  main  trunk  of  a 
woody  structure   are   called   trees.     Shrubs 
differ  from  trees  in  their  smaller  size,  and 

generally  in  having  several  stems  which  proceed  from  the 
ground  or  near  it  or  in  having  much-forked  stems.  The 
witch-hazel,  the  dogwoods,  and  the  alders,  for  instance, 
are  most  of  them  classed  as  shrubs  for  this  reason,  though 
in  height  some  of  them  equal  the  smaller  trees.  Some  of 


FIG.  34.  —  Leaf -Bearing  Spine 
of  Honey  Locust. 


70 


FOUNDATIONS   OF  BOTANY 


the  smallest  shrubby  plants,  like  the  dwarf  blueberry,  the 
wintergreen,  and  the  trailing  arbutus,  are  only  a  few  inches 


FIG.  35.  —  Tip  of  a  Branch  of  Magnolia,  illustrating  Forking  due  to 
Terminal  Flower-Buds. 

A,  oldest  flower-bud  scar  ;   £,  C,  D,  scars  of  successive  seasons  after  A;  L,  leaf- 
buds  ;  F,  flower-buds. 

in  height,  but  are  ranked  as  shrubs  because  their  woody 
stems  do  not  die  quite  to  the  ground  in  winter. 

Herbs  are  plants  whose  stems  above  ground  die  every 
winter. 


STEMS 


71 


86.  Annual,  Biennial,  and  Perennial  Plants.  —  Annual 
plants  are  those  which  live  but  one  year,  biennials  those 
which  live  two  years 
or  nearly  so. 

Some  annual  plants 
may  be  made  to  live 
over  winter,  flower- 
ing in  their  second 
summer.  This  is  true 
of  winter  wheat  and 
rye  among  cultivated 
plants. 

Perennial  plants  live  for  a  series  of 
years.  Many  kinds  of  trees  last  for 
centuries.  The  Californian  giant  redwoods,  or  Sequoias 
(Fig.  32),  which  reach  a  height  of  over  300  feet  under 
favorable  circumstances,  live  nearly  2000  years ;  and  some 


\ 


FIG.  36.  —A  Portion  of 

the  Branch  of  Fig.  35. 

(Natural  size.) 


L—  Twigs  and 
Branches  of  the 
Birch. 


monstrous  cypress  trees  found  in  Mexico  were  thought  by 
Professor  Asa  Gray  to  be  from  4000  to  5000  years  old. 


72 


FOUNDATIONS   OF   BOTANY 


87.  Stemless  Plants.  —  As  will  be  shown  later  (Chap- 
ter XXX),  plants  live  subject  to  a  very  fierce  competition 
among  themselves  and  exposed  to  almost  constant  attacks 
from  animals. 

While  plants  with  long  stems  find  it  to  their  advantage 
to  reach  up  as  far  as  possible  into  the  sunlight,  the  cinque- 
foil,  the  white  clover, 
the  dandelion,  some 
spurges,  the  knot- 
grass, and  hundreds 
of  other  kinds  of 
plants  have  found 
safety  in  hugging 
the  ground. 

Any  plant  which 
can  grow  in  safety 

Undei>  the  veiyfeet 
4k<*9Hi      I"-  ^  of   grazing    animals 

will  be  especially 
likely  to  make  its 
way  in  the  world, 
since  there  are  many 
places  where  it  can 
flourish  while  ordi- 
nary plants  would  be  destroyed.  The  bitter,  stemless 
dandelion,  which  is  almost  uneatable  for  most  animals, 
unless  cooked,  which  lies  too  near  the  earth  to  be  fed 
upon  by  grazing  animals,  and  which  bears  being  trodden 
on  with  impunity,  is  a  type  of  a  large  class  of  hardy  weeds. 
The  so-called  stemless  plants,  like  the  dandelion  (Fig.  38), 
and  some  violets,  are  not  really  stemless  at  all,  but  send 


FIG.  38.  —The  Dandelion  ;  a  so-called 
Stemless  Plant. 


STEMS 


73 


out  their  leaves  and  flowers  from  a  very  short  stem,  which 
hardly  rises  above  the  surface  of  the  ground. 

88.  Climbing  and  Twining  Stems.1  —  Since  it  is  essen- 
tial to  the  health  and  rapid  growth  of  most  plants  that 
they  should  have  free  access 
to  the  sun  and  air,  it  is  not 
strange  that  many  should 
resort  to  special  devices  for 
lifting  themselves  above 
their  neighbors.  In  tropi- 
cal forests,  where  the  dark- 
ness of  the  shade  anywhere 
beneath  the  tree-tops  is  so 
great  that  few  flowering 
plants  can  thrive  in  it,  the 
climbing  plants  or  lianas 
often  run  like  great  cables 
for  hundreds  of  feet  before 
they  can  emerge  into  the  sun- 
shine above.  In  temperate 
climates  no  such  remarkable 
climbers  are  found,  but  many 
plants  raise  themselves  for 
considerable  distances.  The 
principal  means  to  which  they  resort  for  this  purpose  are  : 

(1)  Producing   roots    at   many   points  along  the  stem 
above  ground  and  climbing  on  suitable  objects  by  means 
of  these,  as  in  the  English  ivy  (Fig.  15). 

(2)  Laying  hold  of    objects  by  means   of    tendrils   or 
twining  branches  or  leaf -stalks,  as  shown  in  Figs.  40,  41. 

1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  p.  669. 


FIG.  39.  —Lianas  strangling  a  Palm. 


74 


FOUNDATIONS   OF   BOTANY 


(3)  Twining  about  any  slender  upright  support,  as 
shown  in  Fig.  42. 

89.  Tendril-Climbers.  —  The  plants  which  climb  by 
means  of  tendrils  are  important  subjects  for  study,  but 
they  cannot  usually  be  managed  very  well  in  the  school- 
room. Continued  observation  soon  shows  that  the  tips  of 

tendrils  sweep  slowly  about  in 
the  air  until  they  come  in  contact 
with  some  object  about  which 
they  can  coil  themselves.  After 
the  tendril  has  taken  a  few  turns 
about  its  support,  the  free  part  of 
the  tendril  coils  into  a  spiral  and 
thus  draws  the  whole  stem  toward 
the  point  of  attachment,  as  shown 
in  Fig.  40.  Some  tendrils  are 
modified  leaves  or  stipules,  as 
shown  in  Fig.  104  ;  others  are 
modified  stems. 

90.  Twiners.  —  Only  a  few  of 
the  upper  internodes  of  the  stem 
of  a  twiner  are  concerned  in  pro- 
ducing the  movements  of  the  tip 
of  the  stem.  This  is  kept  revolving  in  an  elliptical  or 
circular  path  until  it  encounters  some  roughish  and  not  too 
stout  object,  about  which  it  then  proceeds  to  coil  itself. 

The  movements  of  the  younger  internodes  of  the  stems 
of  twiners  are  among  the  most  extensive  of  all  the  move- 
ments made  by  plants.  A  hop-vine  which  has  climbed  to 
the  top  of  its  stake  may  sweep  its  tip  continually  around 
the  circumference  of  a  circle  two  feet  in  diameter,  and  the 


FIG  40.  — Coiling  of  a  Tendril 
of  Bryony. 


STEMS 


75 


common  wax-plant  of  the  greenhouses  sometimes  describes 
a  five-foot  circle,  the  tip  moving  at  the  rate  of  thirty-two 
inches  per  hour.1  This  circular  motion  results  from 
some  cause  not  yet  fully  understood  by  botanists.2 

The  direction  in  which  twiners  coil  about  a  supporting 
object  is  almost  always  the  same  for  each  species  of  plant, 
but  not  the  same  for  all 
species.  In  the  hop  it  is  as 


FIG.  41.  —Coiling  of  Petiole  of  Dwarf 
Tropaeolmu. 


FIG.  42.  —  Twining  Stem  of  Hop. 


shown  in  Fig.  42.  Is  it  the  same  as  in  the  bean  ?  in  the 
morning-glory  ? 

91.  Underground  Stems.  —  Stems  which  lie  mainly  or 
wholly  underground  are  of  frequent  occurrence  and  of 
many  kinds. 

In  the  simplest  form  of  rootstock  (Fig.  43),  such  as  is 

1  See  article  on  Climbing  Plants,  by  Dr.  W.  J.  Beal,  in  the  American 
Naturalist,  Vol.  IV,  pp.  405-415. 

2  See  Strasburger,  Noll,  Schenk,   and  Schimper,  Text-Book,  pp.  258-262  ; 
also  Vines,  Students'  Text-Book  of  Botany,  London  and  New  York,  1894, 
pp.  759,  760. 


76 


FOUNDATIONS   OF   BOTANY 


found  in  some  mints  and  in  many  grasses  and  sedges,  the 
real  nature  of  the  creeping  underground  stem  is  shown  by 

the  presence  upon  its  sur- 
face of  many  scales,  which 
are  reduced  leaves.  Root- 
stocks  of  this  sort  often 
extend  horizontally  for 
long  distances  in  the  case 
of  grasses  like  the  sea  rye 
grass  (Plate  I),  which  roots 
itself  firmly  and  thrives  in 
shifting  sand-dunes.  In 
the  stouter  rootstocks,  like 
that  of  the  iris  (Fig.  44) 
and  the  Caladium  (Fig. 
45),  this  stem-like  charac- 
ter is  less  evident.  The 
potato  is  an  excellent  ex- 
ample of  the  short  and 
much-thickened  under- 
ground stem  known  as  a 
tuber. 

It  may  be  seen  from  Fig. 
46   that  the   potatoes  are 
none  of  them  borne  on  true 
roots,  but  only  on  subter- 
ranean 
branches, 
which  are 

FlG.  43.  — Kootstock  of  Cotton-Grass  (Eriophorum).  S  to  U  t  6  f 

and  more  cylindrical  than  most  of  the  roots.     The  "  eyes  " 


1 


STEMS 


77 


which  they  bear  are  rudi- 
mentary leaves  and  buds. 

Bulbs,  whether  coated 
like  those  of  the  onion  or 
the  hyacinth  (Fig.  47),  or 
scaly  like  those  of  the 
lily,  are  merely  very  short 
and  stout  underground 
stems,  covered  with  closely 
crowded  scales  or  layers 
which  represent  leaves  or 
the  bases  of  leaves  (Fig.  48). 

The  variously  modified 
forms  of  underground 
stems  just  discussed,  illus- 


FIG.  44.  — Roots,  Rootstocks,  and 
Leaves  of  Iris. 

trate  in  a  marked  way  the  storage 
of  nourishment  during  the  winter 
(or  the  rainless  season,  as  the  case 
may  be)  to  secure  rapid  growth  dur- 
ing the  active  season.  It  is  inter- 
esting to  notice  that  nearly  all  of 
the  early-flowering  herbs  in  temper- 
ate climates,  like  the  crocus,  the 
snowdrop,  the  spring-beauty,  the 


FIG.  45. — Rootstock  of  Cala- 
dium  (Colocasia). 

b,  terminal  bud  ;  b',  buds  ar- 
ranged in  circles  where  bases 
of  leaves  were  attached ;  s, 
scars  left  by  sheathing  bases 
of  leaves. 


78 


FOUNDATIONS   OF   BOTANY 


tulip,  and  the  skunk-cabbage,  owe  their  early-blooming 
habit  to  richly  stored  underground  stems  of  some  kind, 
or  to  thick,  fleshy  roots. 

92.  Condensed  Stems.  —  The  plants  of  desert  regions 
require,  above  all,  protection  from  the  extreme  dryness  of 
the  surrounding  air,  and,  usually,  from  the  excessive  heat 

of  the  sun.  Ac- 
cordingly, many 
desert  plants  are 
found  quite  desti- 
tute of  ordinary 
foliage,  exposing 
to  the  air  only  a 
small  surface.  In 
the  melon-cactuses 
(Fig.  49)  the  stem 
appears  reduced 
to  the  shape  in 
which  the  least 
possible  surface  is 
Fw.-.o.-part  of  a  Potato  piant.  presented  by  a 

The  dark  tuber  in  the  middle  is  the  one  from  which        plant    of    give  11 
the  plant  has  grown.  j^  _  ^  ^  ^ 

a  globular  form.  Other  cactuses  are  more  or  less  cylindri- 
cal or  prismatic,  while  -  still  others  consist  of  flattened 
joints ;  but  all  agree  in  offering  much  less  area  to  the  sun 
and  air  than  is  exposed  by  an  ordinary  leafy  plant. 

93.  Leaf -Like  Stems. — The  flattened  stems  of  some  kinds 
of  cactus  (especially  the  common,  showy  Phyllocactus)  are 
sufficiently  like  fleshy  leaves,  with  their  dark  green  color 
and  imitation  of  a  midrib,  to  pass  for  leaves.     There  are, 


STEMS 


79 


Jblu.  47.  —  Bulb  of  Hyacinth. 
(Exterior  view  and  split  lengthwise.) 


however,  a  good  many  cases  in  which  the  stem  takes  on 

a  more  strikingly  leaf-like  form.     The  common  asparagus 

sends  up  in  spring  shoots 
that  bear  large  scales  which 
are  really  reduced  leaves. 
Later  in  the  season,  what 
seem  like  thread-like  leaves 
cover .  the  much-branched 
mature  plant,  but  these 
green  threads 
are  actually  mi- 
nute branches, 
which  perform 
the  work  of 

leaves    (Fig.   50).      The   familiar    greenhouse 

climber,   wrongly  known  as  smilax  (properly 

called    Myrsipliyllum),    bears    a   profusion    of 

what    appear    to    be    delicate    green    leaves 

(Fig.  51).     Close  study,  however,  shows  that 

these  are  really  short,  flattened  branches, 

and  that  each  little  branch  springs  from 

the  axil  of  a  true   leaf,   ?,   in   the  form 

of  a  minute  scale.     Sometimes  a  flower 

and  a  leaf-like   branch  spring  from   the 

axil  of  the  same  scale. 

1    Branches  which,  like  those   of   Myrsi- 

phyllum,  so  closely  resemble  leaves  as  to 

be  almost  indistinguishable  from  them  are 

called  cladophylls. 

94.    Modifiability  of  the  Stem. — The  stem  may,  as  in  the 

tallest  trees,  in  the  great  lianas  of  South  American  forests, 


sea 


FlG.  48.  —  Longitu- 
dinal Section  of 
an  Onion  Leaf. 

sea,  thickened  base 
of  leaf,  forming  a 
bulb-scale;  s,thin 
sheath  of  leaf  ;  bl, 
blade  of  the  leaf  ; 
int,  hollow  inte- 
rior of  blade. 


80 


FOUNDATIONS   OF   BOTANY 


&£. 

, 


FIG.  50.  —A  Spray  of  a  Common  Asparagus  (not  the  edible  species). 


STEMS 


81 


or  the  rattan  of  Indian  jungles,  reach  a  length  of  many 
hundred  feet.  On  the  other  hand,  in  such  "stemless" 
plants  as  the  primrose  and  the  dandelion,  the  stem  may  be 
reduced  to  a  fraction  of  an  inch  in  length.  It  may  take 


FIG.  51.  —  Stem  of  "  Smilax  "  (Myrsiphyllum). 

I,  scale-like  leaves ;  cl,  cladophyll,  or  leaf-like  branch,  growing  in  the  axil  of  the 
leaf  ;  ped,  flower-stalk,  growing  in  the  axil  of  a  leaf. 

on  apparently  root-like  forms,  as  in  many  grasses  and 
sedges,  or  become  thickened  by  underground  deposits  of 
starch  and  other  plant-food,  as  in  the  iris,  the  potato,  and 
the  crocus.  Condensed  forms  of  stem  may  exist  above 
ground,  or,  on  the  other  hand,  branches  may  be  flat  and 


82  FOUNDATIONS   OF   BOTANY 

thin  enough  closely  to  imitate  leaves.  In  short,  the  stem 
manifests  great  readiness  in  adapting  itself  to  the  most 
varied  conditions  of  existence. 

95.    Review  Summary  of  Stems.1 
Kinds  of  branching  due  to  leaf  arrangement      ....      J 


Kinds  of  tree-trunk  due  to  greater  or  less  predominance       f  1  - 
of  terminal  bud .       [2. 

f1- 

Classes  of  plants  based  on  amount  of  woody  stem      .     .      -j  2. 

U 
f1- 

Classes  of  plants  based  on  duration  of  life •<  2. 

Is. 

f1- 

Various  modes  of  climbing -^2. 

U. 
f1- 

Kinds  of  underground  stem ^2. 


Condensed  stems  above  ground 


Leaf-like  stems 


1  Where  it  is  possible  to  do  so,  make  sketches ;  where  this  is  not  possible, 
give  examples  of  plants  to  illustrate  the  various  kinds  or  classes  of  plants  in 
the  summary. 


CHAPTER    VI 


STRUCTURE    OF   THE    STEM 


STEM   OF   MONOCOTYLEDONOUS   PLANTS 

96,  Gross  Structure.  —  Refer  back  to  the  sketches  of  the  corn- 
seedling,  to  recall  something  of  the  early  history  of  the  -corn-stem. 
Study  the  external  appearance  of  a  piece  of  corn-stem  or  bamboo 
two  feet  or  more  in  length.  Note  the  character  of  the  outer  surface. 
Sketch  the  whole  piece  and  label  the  enlarged  nodes  and  the  nearly 
cylindrical  internodes.  Cut  across  a  corn-stem  and  examine  the  cut  sur- 
face with  the  magnifying  glass. 
Make  some  sections  as  thin  as 
they  can  be  cut  and  examine 
with  the  magnifying  glass 
(holding  them  up  to  the  light) 
or  with  a  dissecting  microscope. 
Note  the  firm  rind,  composed 
of  the  epidermis  and  underlying 
tissue,  the  large  mass  of  pith 
composing  the  main  bulk  of  the 
stem,  and  the  many  little  harder 
and  more  opaque  spots,  which 
are  the  cut-off  ends  of  the 
woody  threads  known  asj^ftro- 
vascular  bundles  (Fig.  52). 

Split  a  portion  of  the  stern 
lengthwise  into  thin  translucent 
slices  and  notice  whether  the 
bundles  seem  to  run  straight  up  and  down  its  length ;  sketch  the 
entire  section  x  2.  Every  fibro-vascular  bundle  of  the  stem  passes  out- 
ward through  some  node  in  order  to  connect  with  some  fibro-vascular 


FIG.  52.  — Diagrammatic  Cross-Section 

of  Stem  of  Indian  Corn. 

cv,  fibro-vascular  bundles  ;  gc,  pithy  material 

between  bundles. 


84  FOUNDATIONS  OF  BOTANY 

bundle  of  a  leaf.  This  fact  being  known  to  the  student  would  lead 
him  to  expect  to  find  the  bundles  bending  out  of  a  vertical  position 
more  at  the  nodes  than  elsewhere.  Can  this  be  seen  in  the  stem 
examined  ? 

Observe  the  enlargement  and  thickening  at  the  nodes,  and  split 
one  of  these  lengthwise  to  show  the  tissue  within  it. 

Compare  with  the  corn-stem  a  piece  of  palmetto  and  a  piece  of 
cat-brier  (Smilax  rotundifolia,  S.  hispida,  etc.),  and  notice  the  simi- 
larity of  structure,  except  for  the  fact  that  the  tissue  in  the  palmetto 
and  the  cat-brier  which  answers  to  the  pith  of  the  corn-stem  is  much 
darker  colored  and  harder  than  corn-stem  pith.  Compare  also  a  piece 
of  rattan  and  of  bamboo. 

97.  Minute  Structure.  —  Cut  a  thin  cross-section  of  the  corn-stem, 
examine  with  a  low  power  of  the  microscope,  and  note : 

(a)  The  rind  (not  true  bark),  composed  largely  of  hard,  thick- 
walled  dead  cells,  known  as  sclerenchyma  fibers. 

(6)  The  fibro-vascular  bundles.  Where  are  they  most  abundant  ? 
least  abundant  ? 

(c)  The  pith,  occupying  the  intervals  between  the  fibro-vascular 
bundles. 

Study  the  bundles  in  various  portions  of  the  section  and  notice 
particularly  whether  some  are  more  porous  than  others.     Explain. 
Sketch  some  of  the  outer  and  some  of  the 
inner  ones. 

A  more  complicated  kind  of  monocoty- 
ledonous  stem-structure  can  be  studied  to 
advantage  in  the  surgeons'  splints  cut  from 
yucca-stems  and  sold  by  dealers  in  surgical 
supplies. 

FIG.  53. -Diagrammatic         98«   Mechanical     Function    of    the 
cross-section  of  stem  of     Manner   of    Distribution   of   Material 

Bulrush   (Scirpus),  a        . 

Hollow  cylinder  with     in    Monocotyledonous    Stems.  —  The 
strengthening  Fibers.       weU-known  strength  and  lightness  of 

the  straw  of  our  smaller  grains  and  of  rods  of  cane  or 
bamboo  are  due  to  their  form.  It  can  readily  be  shown 


STRUCTURE   OF  THE   STEM 


85 


by  experiment  that  an  iron  or  steel  tube  of  moderate  thick- 
ness, like  a  piece  of  gas-pipe,  or  of  bicycle-tubing,  is  much 
stiffer  than  a  solid  rod  of  the  same  weight  per  foot.  The 
oat  straw,  the  stems  of  bulrushes  (Fig.  53),  the  cane  (of 
our  southern  canebrakes),  and  the  bamboo  are  hollow 
cylinders  ;  the 
cornstalk  is  a 
solid  cylinder, 
but  filled  with  a 
very  light  pith. 
The  flinty  outer 
layer  of  the 
stalk,  together 
with  the  closely 
packed  scleren- 
chyma  fibers  of 
the  outer  rind 
and  the  frequent 
fibro-vascular 
bundles  just 
within  this,  are 
arranged  in  the 
best  way  to  se- 
cure stiffness. 
In  a  general 
way,  then,  we  may  say  that  the  pith,  the  bundles,  and  the 
sclerenchymatous  rind  are  what  they  are  and  where  they 
are  to  serve  important  mechanical  purposes.  But  they 
have  other  uses  fully  as  important  (Fig.  78). 

99.    Growth  of  Monocotyledonous  Stems  in  Thickness.  - 
In    most    woody    monocotyledonous  stems,   for  a  reason 


FIG.  54.  —  Group  of  Date-Palms. 


86  FOUNDATIONS   OF   BOTANY 

which  will  be  explained  later  in  this  chapter,  the  increase 
in  thickness  is  strictly  limited.  Such  stems,  therefore,  as 
in  many  palms  (Fig.  54)  and  in  rattans,  are  less  conical 
and  more  cylindrical  than  the  trunks  of  ordinary  trees 
and  are  also  more  slender  in  proportion  to  their  height. 


STEM   OF   DICOTYLEDONOUS   PLANTS 

100.  Gross  Structure  of  an  Annual  Dicotyledonous  Stem.  —  Study 
the  external  appearance  of  a  piece  of  sunflower-stem  several  inches 
long.     If  it  shows  distinct  nodes,  sketch  it.     Examine  the  cross- 
section  and  sketch  it  as  seen  with  the  magnifying  glass  or  the  dissect- 
ing microscope.    After  your  sketch  is  finished,  compare  it  with  Fig.  55, 
which  probably  shows  more  details  than  your  drawing,  and  label 
the  parts  shown  as  they  are  labeled  in  that  figure.     Split  a  short 
piece  of  the  stem  lengthwise  through  the  center  and  study  the  split 
surface  with  the  magnifying  glass.     Take  a  sharp  knife  or  a  scalpel 
and  carefully  slice  and  then  scrape  away  the  bark  until  you  come  to 
the  outer  surface  of  a  bundle. 

Examine  a  vegetable  sponge  (Luffd),  sold  by  druggists,  and  notice 
that  it  is  simply  a  network  of  fibro-vascular  bundles.  It  is  the  skele- 
ton of  a  tropical  seed-vessel  or  fruit,  very  much  like  that  of  the  wild 
cucumber,  common  in  the  Central  States,  but  a  great  deal  larger. 

The  different  layers  of  the  bark  cannot  all  be  well  recognized  in  the 
examination  of  a  single  kind  of  stem.  Examine  (a)  the  cork  which 
constitutes  the  outer  layers  of  the  bark  of  cherry  or  birch  branches 
two  or  more  years  old.  Sketch  the  roundish  or  oval  spongy  lenticels 
on  the  outer  surface  of  the  bark.  How  far  in  do  they  extend  ?  Exam- 
ine (6)  the  green  layer  of  bark  as  shown  in  twigs  or  branches  of 
Forsythia,  cherry,  alder,  box-elder,  wahoo,  or  willow.  Examine  (c) 
the  white,  fibrous  inner  layer,  known  as  hard  bast,  of  the  bark  of 
elm,  leatherwood,  pawpaw,  or  basswood. 

101.  Minute  Structure  of  the  Dicotyledonous  Stem.  —  Study,  first 
with  a  low  and  then  with  a  medium  power  of  the  compound  micro- 
scope, thin  cross-sections  of  clematis-stem  cut  just  before  the  end  of 


STRUCTURE   OF   THE   STEM 


87 


the  first  season's  growth.1  Sketch  the  whole  section  without  much 
detail,  and  then  make  a  detailed  drawing  of  a  sector  running  from 
center  to  circumference  and  just  wide  enough  to  include  one  of  the 
large  bundles.  Label  these  drawings  in  general  like  Figs.  55,  56. 


FIG.  55.  —  Diagrammatic  Cross-Section  of  an  Annual  Dicotyledonous  Stem. 
(Somewhat  magnified.) 

p,  pith  ;  fv,  woody  or  fibro-vascular  bundles  ;  e,  epidermis  ;   b,  bundles  of  hard 
bast  fibers  of  the  bark. 


FIG.  56.  —Diagrammatic  Cross-Section  of  One- Year-Old  Aristolochia  Stem. 
(Considerably  magnified.) 

e,  region  of  epidermis ;  6,  hard  bast ;  o,  outer  or  bark  part  of  a  bundle  (the 
cellular  portion  under  the  letter) ;  w,  inner  or  woody  part  of  bundle  ;  c,  cam- 
bium layer  ;  p,  region  of  pith  ;  m,  a  medullary  ray. 

The  space  between  the  hard  bast  and  the  bundles  is  occupied  by  thin-walled, 
•  somewhat  cubical  cells  of  the  bark. 


1  Clematis  virginiana  is  simpler  in  structure  than  some  of  the  other  woody 
species.     Aristolochia  sections  will  do  very  well. 


88 


FOUNDATIONS   OF   BOTANY 


Note: 

(a)  The  general  outline  of  the  section. 

(6)  The  number  and  arrangement  of   the  bundles.      (How 
many  kinds  of  bundles  are  there?) 

(c)  The  comparative  areas  occupied  by  the  woody  part  of  the 

bundle  and  by  the  part  which  belongs  to  the  bark. 

(d)  The  way  in  which  the  pith  and  the  outer  bark  are  con- 

nected (and  the  bundles  separated)  by  the  medullary  rays. 


FIG.  57.  —  One  Bundle  from  the  Preceding  Figure,    (x  100.) 

w,  wood-cells  ;  d,  ducts.    The  other  letters  are  as  in  Fig.  56.    Many  sieve-cells 
occur  in  the  region  just  outside  of  the  cambium  of  the  bundle. 

Examine  a  longitudinal  section  of  the  same  kind  of  stem,  to  find 
out  more  accurately  of  what  kinds  of  cells  the  pith,  the  bundles,  and 
the  outer  bark  are  built.  Which  portion  has  cells  that  are  nearly 
equal  in  shape,  as  seen  in  both  sections  V 


STRUCTURE   OF   THE   STEM 


89 


102.  Mechanical  Importance  of  Distribution  of  Material 
in  the  Dicotyledonous  Stem.  —  It  is  easy  to  see  that  those 
tissues  which  are  tough,  like  hard  bast,  and  those  which 
are  both  tough  and  stiff,  like  wood  fibers,  are  arranged  in 
a  tubular  fashion  in  young  dicotyledonous  stems  as  they 
are  in  some  monocotyledonous  ones  (Fig.  53).  Sometimes 
the  interior  of  the  stem  is  quite  hollow,  as,  for  example, 


B 


e  ck 


c     w    d    m 


FIG.  58.  —  Stem  of  Box-Elder  One  Year  Old.    (Much  magnified.) 
A,  lengthwise  (radial)  section  ;  B,  cross-section  ;  e,  epidermis  ;  ck,  cork  ;  6,  hard 
bast ;    s,  sieve-cells  ;    c,  cambium  ;    w,  wood-cells  ;   m,  medullary  rays  ;    d, 
ducts  ;  p,  pith. 

in  the  stems  of  balsams,  melons,  cucumbers,  and  squashes, 
and  in  the  flower-stalks  of  the  dandelion.  In  older  stems, 
such  as  the  trunks  of  trees,  the  wood  forms  a  pretty  nearly 
solid  cylinder. 

Stiffness  in  dicotyledonous  stems  is  secured  mainly  in 
two  ways:*(l)  by  hard  bast  fibers,  (2)  by  wood  fibers. 
Which  of  these  types  does  the  stem  (Fig.  55)  represent? 
Which  does  the' flax-stem  (Fig.  60)  represent? 


90  FOUNDATIONS   OF   BOTANY 

Notice  that  in  both  types  bast  fibers  and  wood  fibers  are 
present,  but  the  proportions  in  (1)  and  (2)  vary  greatly. 

103,  Kinds  of  Cells  which  compose  Stems.  —  The  stu- 
dent has  already  seen  something  of  cells  in  the  seed,  in 
the  foots  of  seedlings  and  mature  plants,  and  in  several 
kinds  of  stems.  But  he  will  need  to  become  acquainted 
with  a  much  larger  variety  of  cells  in  the  stem.  The  fol- 
lowing materials  will  serve  to  illustrate  some  of  the  most 
important  forms.1 

Examine,  with  a  half-inch  objective  and  one-inch  eyepiece  (or 
higher  power)  these  preparations  (1-9  below)  : 

Study  very  carefully  each  of  the  sections  described,  find  in  it 
the  kind  of  cell  referred  to  in  the  corresponding  number  (1-9)  of 
the  following  section  (104),  and  make  a  good  sketch  of  a  group  of 
cells  of  each  kind  as  actually  seen  under  the  microscope.2 

(1)  Very  thin  sections  of  the  epidermis  of  a  potato,  some  cut  parallel 
to  the  surface  (tangential),  others  cut  at  right  angles  to  the  epidermis. 

(2)  Thin  sections  of  the  green  layer  of  the  bark  of  Forsythia, 
spindle  tree  (Euonymus),  or  box-elder  (Negundo). 

(3)  Thin  cross-sections  and  longitudinal  sections  of  the  inner  bark 
of  linden  twigs,  or  of  full-grown  stems  of  flax. 

(4)  Longitudinal  sections  of  the  stem  of  squash  or  cucumber  plants. 

(5)  Thin  cross-sections  of  young  twigs  of  pine  or  oak,  cut  in  late 
summer. 

(6)  Thin  cross-sections  and  longitudinal  sections,  cut  from  pith 
toward  bark  (radial)  of  young  wood  of  sycamore,  of  sassafras,  or  of 
box-elder. 

(7)  Thin  longitudinal  sections  of  the   stem  of  castor-oil  plant 
(Ricinus)    or  of   the    stalk    (peduncle)   on  which  the  fruit  of    the 
banana  is  supported. 

1  These  studies  may  be  made  from  sections  cut  by  the  pupil,  by  the  teacher,  or 
by  a  professional  hand,  as  circumstances  may  dictate.    The  soft  bast  (No.  4,  see 
p.  91)  can  best  be  studied  in  good  prepared  sections  obtained  of  the  dealers. 

2  Nothing  can  do  so  much  to  make  these  studies  valuable  as  for  the  teacher 
to  correct  in  class  the  errors  of  most  frequent  occurrence  in  the  drawings,  by 
aid  of  his  own  camera  lucida  drawings  of  the  same  objects. 


STRUCTURE   OF  THE   STEM 


91 


(8)  Thin  longitudinal  radial  sections  of  sycamore,  of  sassafras, 
maple,  or  box-elder  wood. 

(9)  Thin  sections  of  elder  pith,  sunflower-stem  pith,  or  of  so-called 
Japanese  "  rice-paper." 

104.    Names  of  the  Cells  of  Bark,  Wood,  and  Pith.— No 
two  varieties  of  stems  will  be  found  to  consist  of  just  the 


FIG.  59.  — .4,  B,  C, 
D,  Isolated  Wood- 
Cells  and  Bast- 
Cells  of  Linden. 

A,  B,  wood  fibers  ;  C, 
piece  of  a  vessel; 
Z>,  bast  fiber;  E,  a 
partitioned,  woody 
fiber  from  Euro- 
pean ivy.  (Much 
magnified.) 


FIG.  60.  —  Part  of  Cross-Section  of  Stem  of  Flax. 
(Much  magnified.) 

e,  epidermis  ;   b,  hard  bast ;  s,  sieve-cells  ;  w,  wood. 

same  kinds  of  cells,  present  in  the  same 
proportions,  but  it  is  easy  to  refer  to  illus- 
trations which  will  serve  to  identify  the 
kinds  of  cells  found  in  the  studies  of  the 
preceding  section.  They  are  : 

(1) 


Cork-cells    of    the    epidermis    (e.g.,    flax, 
Fig.  60,  e). 

(2)  Cells  of  the  green  bark  (e.g.,  flax,  Fig.  60), 

between  b  and  e. 

(3)  Hard  bast  (Fig.  60). 

(4)  Soft  bast  (e.g.,  flax,  Fig.  60,  s,  for  the  cross-section  and  (very 
greatly  magnified)  Figs.  63,  64,  for  the  lengthwise  section).1 

1  The  sieve-tubes  shown  in  these  figures  are  only  one  of  several  kinds  of 
cell  found  in  soft  bast,  but  they  are  the  most  peculiar  and  characteristic  ones. 
(See  Strasburger,  Noll,  S,chenk,  and  Schimper's  Text-Book,  pp.  102-104.) 


92 


FOUNDATIONS   OF   BOTANY 


(5)  Cambium  (e.g.,  Fig.  57,  c). 

(6)  Wood-cells  (e.g.,  Figs.  58,  72-73). 

(7)  Vessels  or  ducts  (e.g.,  Figs.  58  and  62). 

(8)  Wood  parenchyma  (e.g.,  Figs.  58  and  72  in  the  medullary 

rays). 

(9)  Pith  (e.g.,  Figs.  55,  57). 

105.    Structure  of  Coniferous  Wood In  the  wood   of 

the  cone-bearing  trees  of  the  pine  family  regular  ducts  or 


FlG.  61.  FlG.,62. 

FIG.  61.  —  A  Group  of  Hard  Bast  Fibers.     (Greatly  magnified.) 
a,  cut-off  ends  ;  b,  lengthwise  section  of  fibers. 

FlG.  62.  —  A  Lengthwise  Section  (greatly  magnified)  of  a  Group  of  Spiral  Vessels 
from  the  Stem  of  Sunflower.  At  the  top  of  the  figure  some  of  the  spiral 
threads  which  line  the  vessels  are  seen  partly  uncoiled. 

vessels  are  lacking.     The  main  bulk  of  the  wood  is  com- 
posed of  long  cells  (often  called  tracheids),  marked  with 


STRUCTURE    OF   THE   STEM 


93 


peculiar  pits.  These  pits,  when  young,  are  shaped  much 
like  two  perforated  watch-glasses,  placed  against  a  piece 
of  cardboard,  with  their  concave  sides  toward  each  other 


FIG.  63.  FIG.  64. 

FIG.  63.  —  Part  of  a  Sieve-Tube  from  Linden. 
*,  sieve-plates  on  the  cell- wall,    (x  about  900.) 

FIG.  64.  —  Parts  of  Sieve-Tubes  as  found  in  Plants  of  the  Gourd  Family. 

(Greatly  magnified.) 
s,  s,  a  sieve-plate  seen  edgewise  ;  above  it  a  similar  one,  surface  view. 


FIG.  65.  —Cross-Section  of  Fir  Wood. 
s,  a  resin  passage  ;  m,  medullary  rays.    (Much  magnified.) 


94 


FOUNDATIONS   OF   BOTANY 


(see  Fig.  66,  t").  The  cardboard  represents  a  part  of  the 
cell-wall  common  to  two  adjacent  cells,  and  the  watch- 
glasses  are  like  the  convex  border  bulging  into  each  cell. 

When  the  cells  grow  old  the 
partition  in  each  pit  very  com- 
monly breaks  away  and  leaves 
a  hole  in  the  cell-wall. 

106.  Tissues.  —  A  mass  of 
similar  cooperating  cells  is  called 
a  tissue.1  Two  of  the  principal 
classes  which  occur  in  the  stem 
are  parenchymatous  tissue  and 
prosenchymatous  tissue.  Paren- 
chyma  is  well  illustrated  by  the 
green  layer  of  the  bark,  by  wood 
parenchvma,  and  by  pith.  Its 
ce^s  are  usually  somewhat 
roundish  or  cubical,  at  any  rate 
not  many  times  longer  than  wide, 
and  at  first  pretty  full  of  proto- 
plasm. Their  walls  are  not 
generally  very  thick.2  Prosen- 
chyma,  illustrated  by  hard  bast 
and  masses  of  wood-cells,  con- 
sists of  thick-walled  cells  many 
times  longer  than  wide,  containing  little  protoplasm  and 
often  having  little  or  no  cell-cavity. 

As  a  rule  the  stems  of  the  most  highly  developed  plants 
owe  their  toughness  and  their  stiffness  mainly  to  prosen- 


FlG.  66.  —  Longitudinal  Radial  Sec- 
tion through  a  Rapidly  Growing 
Young  Branch  of  Pine. 

t ,  t',  t",  bordered  pits  on  wood-cells  ; 
st,  large  pits  where  medullary 
rays  lie  against  wood-cells. 
(Much  magnified.) 


1  See  Vines'  Students'  Text-Book  of  Botany,  London,  1894,  pp.  131-144. 

2  Excepting  when  they  are  dead  and  emptied,  like  those  of  old  pith. 


STRUCTURE   OF  THE   STEM 


95 


OOL 


FIG.  67o  —  Collenchymatous 

and  Other  Tissue  from  Stem  for  instance, 

of  Balsam  (Impatient^.  ag  the  grow. 

e,  epidermis  ;c,  coll  enchyma;  . 

i,  intercellular  spaces  be-  ing     p 0 1  Ht 

tween   large  parenchyma-  between  the 
cells. 

two  rudi- 
mentary leaves  of  a  bean-plumule, 
the  cells  are  all  of  thin-walled 
formative  tissue  and  look  a  good 
deal  alike.  This  condition  of 
things  is  quickly  succeeded  by 
one  in  which  there  is  a  cylinder 
(appearing  in  cross-sections  of  the 
stem  as  a  ring)  of  actively  growing  FlG 
tissue  x  (Fig.  68,  A),  lying  between 
the  cortex  r  and  the  pith  m.  Soon 
the  cylinder  x  develops  into  a 
series  of  separate  fibro-vascular 
bundles  arranged  as  shown  in 
Fig.  68,  B,  and  these  again  in  a 
short  time  unite,  as  shown  at  0. 
A  comparison  of  this  last  portion 
of  the  figure  with  that  of  the 


chymatous  tissue.  In  some  (particu- 
larly in  fleshy)  stems  the  stiffness  is, 
however,  largely  due  to  collenchyma,  a 
kind  of  parenchyma  in  which  the  cells 
are  thickened  or  reinforced  at  their 
angles,  as  shown  in  Fig.  67. 

107,  Early  History  of  Stem-Struc- 
ture. —  In  the  very  young  parts  of 
stems,  such, 


B 


—  Transverse  Section 
through  the  Hypocotyl  of  the 
Castor-Oil  Plant  at  Various 
Stages. 

,  after  the  root  has  just  ap- 
peared outside  the  testa  of  the 
seed ;  B,  after  the  hypocotyl  is 
nearly  an  inch  long ;  C,  at  the 
end  of  germination ;  r,  cortex 
(undeveloped  bark) ;  m,  pith  ; 
st,  medullary  rays ;  fv,  fibro- 
vascular  bundles ;  cb,  layer  of 
tissue  which  is  to  develop  into 
cambium.  (Considerably  mag- 
nified.) 


96  FOUNDATIONS   OF   BOTANY 

one-year-old  Aristolochia-stem  (Fig.  56)  shows  a  decided 
similarity  between  the  two.  In  both  cases  we  have  the 
central  pith,  the  regularly  grouped  bundles,  and  cambium 
(or  in  Fig.  68,  (7,  a  tissue  which  will  grow  into  cambium), 
-  part  of  it  in  the  bundles  and  part  of  it  between  them. 

In  the  young  monocotyledonous  stem  the  grouping  of 
the  bundles  is  less  regular  than  that  just  explained.  This 
is  shown  by  Fig.  52.  A  much  more  important  difference 
consists  in  the  fact  that  the  monocotyledonous  stem  has 
usually  no  permanent  living  cambium  ring.  Annual  dicoty- 
ledons, however,  are  also  destitute  of  permanent  cambium. 

108.  Secondary  Growth.  —  From  the  inside  of  the  cam- 
bium layer  the  wood-cells  and  ducts  of  the  mature  stem 
are  produced,  while  from  its  outer  circumference  proceed 
the  new  layers  of  the  inner  bark,  composed  largely  of  sieve- 
cells  and  hard  bast.  From  this  mode  of  increase  the  stems 
of  dicotyledonous  plants  are  called  exogenous,  that  is,  out- 
side-growing. The  presence  of  the  cambium  layer  on  the 
outside  of  the  wood  in  early  spring  is  a  fact  well  known 
to  the  schoolboy,  who  pounds  the  cylinder  cut  from  an 
elder,  willow,  or  hickory  branch  until  the  bark  will  slip 
off  and  so  enable  him  to  make  a  whistle.  The  sweet  taste 
of  this  pulpy  layer,  as  found  in  the  white  pine,  the  slippery 
elm,  and  the  basswood,  is  a  familiar  evidence  of  the 
nourishment  which  the  cambium  layer  contains. 

With  the  increase  of  the  fibro-vascular  bundles  of  the 
wood  the  space  between  them,  which  appears  relatively 
large  in  Fig.  68,  becomes  less  and  less,  and  the  pith,  which 
at  first  extended  freely  out  toward  the  circumference  of 
the  stem,  is  at  length  only  represented  by  thin  plates,  the 
medullary  rays. 


STRUCTURE   OF  THE   STEM  97 

These  are  of  use  in  storing  the  food  which  the  plant 
in  cold  and  temperate  climates  lays  up  in  the  summer  and 
fall  for  use  in  the  following  spring,  and  in  the  very  young 
stem  they  serve  as  an  important  channel  for  the  transfer- 
ence of  fluids  across  the  stem  from  bark  to  pith,  or  in  the 


fc 

FIG.  69.  —  Diagram  to  illustrate  Secondary  Growth  in  a  Dicotyledonous  Stem. 

7?,  the  first-formed  bark  ;  p,  mass  of  sieve-cells  ;  ifp,  mass  of  sieve-cells  between 
the  original  wedges  of  wood  ;  fc,  cambium  of  wedges  of  wood  ;  ic,  cambium 
between  wedges  ;  6,  groups  of  bast-cells  ;  fh,  wood  of  the  original  wedges  ; 
ifh,  wood  formed  between  wedges  ;  x,  earliest  wood  formed  ;  M,  pith. 

reverse  direction.  On  account,  perhaps,  of  their  impor- 
tance to  the  plants,  the  cells  of  the  medullary  rays  are 
among  the  longest  lived  of  all  plant-cells,  retaining 
their  vitality  in  the  beech  tree  sometimes,  it  is  said,  for 
more  than  a  hundred  years. 

After  the   interspaces  between  the   first  fibro-vascular 
bundles  have  become  filled  up  with  wood,  the  subsequent 


98  FOUNDATIONS   OF   BOTANY 

growth  must  take  place  in  the  manner  shown  in  Fig.  69. 
All  the  cambium,  both  that  of  the  original  wedges  of  wood, 
fc,  and  that,  ic,  formed  later  between  these  wedges,  con- 
tinues to  grow  from  its  inner  and  from  its  outer  face,  and 
thus  causes  a  permanent  increase  in  the  diameter  of  the  stem 
and  a  thickening  of  the  bark,  which,  however,  usually  at 
an  early  period  begins  to  peel  off  from  the  outside  and 
thus  soon  attains  a  pretty  constant  thickness.1  It  will  be 
noticed,  in  the  study  of  dicotyledonous  stems  more  than  a 
year  old,  that  there  are  no  longer  any  separate  fibre-vascular 
bundles.  The  process  just  described  has  covered  the  origi- 
nal ring  of  bundles  with  layer  after  layer  of  later  formed 
wood-cells,  and  the  wood  at  length  is  arranged  in  a  hollow 
cylinder. 

It  is  the  lack  of  any  such  ring  of  cambium  as  is  found 
in  dicotyledonous  plants,  or  even  of  permanent  cambium 
in  the  separate  bundles,  that  makes  it  impossible  for  the 
trunks  of  most  palm  trees  (Fig.  54)  to  grow  indefinitely 
in  thickness,  like  that  of  an  oak  or  an  elm.2 

109,  Grafting.  —  When  the  cambium  layer  of  any  vigor- 
ously growing  stem  is  brought  in  contact  with  this  layer 
in  another  stem  of  the  same  kind  or  a  closely  similar  kind 
of  plant,  the  two  may  grow  together  to  form  a  single  stem 
or  branch.  This  process  is  called  grafting,  and  is  much 
resorted  to  in  order  to  secure  apples,  pears,  etc.,  of  any 
desired  kind.  A  twig  from  a  tree  of  the  chosen  variety  is 
grafted  on  to  any  kind  of  tree  of  the  same  species  (or  some- 
times a  related  species),  and  the  resulting  stems  will  bear 
the  wished-for  kind  of  fruit.  Sometimes  grafting  comes 

1  See  Vines'  Students'  Text-Book  of  Botany,  London,  1894,  pp.  211,  212. 

2  See,  however,  Strasburger,   Noll,   Schenk   and   Schimper's   Text-Book, 
pp.  138,  139. 


STRUCTURE   OF  THE   STEM 


99 


about  naturally  by  the  branches  of  a  tree  chafing  against  one 
another  until  the  bark  is  worn  away  and  the  cambium  layer 
of  each  is  in  contact  with  that  of  the  other,  or  two  separate 
trees  may  be  joined  by 
natural  grafting,  as  is 
shown  in  Fig.  70. 

110.  Stem-Strircture 
of  Climbing  Shrubs.  — 
Some  of  the  most  remark- 
able kinds  of  dicotyle- 
donous stems  are  found 
in  climbing  shrubs.  The 
structure  of  many  of 
these  is  too  complicated 
to  be  discussed  in  a 
botany  for  beginners,  but 
one  point  in  regard  to 
them  is  of  much  inter- 
est. The  bundles  (as 
seen  in  the  clematis  and 
shown  in  Fig.  56)  are 
much  more  distinct  than 
in  most  other  woody 
stems.  Even  after  sev- 
eral years  of  growth  the 
wood  is  often  found  to  be 
arranged  in  a  number  of 
flattish  twisted  strands. 
It  is  evident  that  this  is  for  the  sake  of  leaving  the 
stem  flexible  for  twining  purposes,  just  as  a  wire  cable  is 
adapted  to  be  wound  about  posts  or  other  supports,  while 


FIG.  70.  —  Two  Ash  Trees  naturally 
grafted  together. 


100 


FOUNDATIONS   OF   BOTANY 


a  solid  steel  or  iron  rod  of  the  same  size  would  be  too 
stiff  for  this  use. 

111.  The  Dicotyledonous  Stem,  thickened  by  Secondary  Growth.  — 
Cut  off,  as  smoothly  as  possible,  a  small  branch  of  hickory  and  one  of 
white  oak  above  and  below  each  of  the  rings  of  scars  already  mentioned 

(Sect.  77),  and  count  the 
P     rings  of  wood  above  and 
below  each  ring  of  scars. 

How  do  the  numbers 
correspond?     What  does 
Phi  this  indicate  ? 

Count  the  rings  of 
wood  on  the  cut-off  ends 
of  large  billets  of  some 
of  the  following  woods; 
locust,  chestnut,  syca- 
more, oak,  hickory. 

Do  the  successive  rings 
of  the  same  tree  agree  in 
thickness  ? 

Why  ?  or  why  not  ? 
Does  the  thickness  of 
the  rings  appear  uniform 
all  the  way  round  the  stick 
of  wood?  If  not,  the  rea- 
son in  the  case  of  an  up- 
right stem  (trunk)  is  per- 
haps that  there  was  a  greater  spread  of  leaves  on  the  side  where  the 
rings  are  thickest l  or  because  there  was  unequal  pressure,  caused  by 
bending  before  the  wind. 

Do  the  rings  of  any  one  kind  of  tree  agree   in   thickness  with 
those  of  all  the  other  kinds  ?     What  does  this  show  ? 
In  all  the  woods  examined  look  for  : 
(a)  Contrasts  in  color  between  the  heartwood  and  the  sapwood.2 

1  See  Sect.  118. 

2  This  is  admirably  shown  in  red   cedar,  black  walnut,   barberry,  black 
locust  and  osage  orange. 


JR 


FIG.  71.  — Cross-Section  of  a  Three- Year-Old 

Linden  Twig.    (M\ich  magnified.) 
P,  epidermis  and  corky  layer  of  the  bark  ;  Phi,  bast ; 
C,  cambium  layer  ;  Jit,  annual  rings  of  wood. 


STRUCTURE   OF  THE   STFJVf 


101 


(b)  The  narrow  lines  running  in  very  young  stems  pretty  straight 
from  pith  to  bark,  in  older  wood  extending  only  a  little  of  the  way 
from  center  to  bark,  the  medullary  rays,  shown  in  Fig.  72. * 

(c)  The  wedge-shaped  masses  of  wood  between  these. 

(c?)  The  pores  which  are  so  grouped  as  to  mark  the  divisions 
between  successive  rings.     These  pores  indicate  the  cross-sections  of 

vessels  or  ducts.  Note  the  dis- 
tribution  of  the  vessels  in  the 
rings  to  which  they  belong,  com- 


FIG.  72.  — Cross-Section  of  Beech-Wood. 
b,  bark  ;  a,  flattened  cells  formed  near 
end  of  each  year's  growth  ;  w,  regu- 
lar wood-cells  ;  m,  medullary  ray. 


FIG.  73.  —  Longitudinal  Section  of 
Mahogany  at  Right  Angles  to 
Medullary  Rays,  showing  Cut- 
off Ends.  (Much  magnified.) 


pare  this  with  Figs.  58,  72,  and  decide  at  what  season  of  the  year 
the  largest  ducts  are  mainly  produced.  Make  a  careful  drawing 
of  the  end-section  of  one  billet  of  wood,  natural  size. 

Cut  off  a  grapevine  several  years  old  and  notice  the  great  size  of 

1  These  and  many  other  important  things  are  admirably  shown  in  the  thin 
wood-sections  furnished  for  $4  per  set  of  24  by  R.  B.  Hough,  Lowville,  N.  Y. 


FOTJOTATIONS   OF   BOTANY 


the  vessels.  Examine  the  smoothly  planed  surface  of  a  billet  of  red 
oak  that  has  been  split  through  the  middle  of  the  tree  (quartered 
oak),  and  note  the  large  shining  plates  formed 
by  the  medullary  rays. 

Look  at  another  stick  that  has  been  planed 
away  from  the  outside  until  a  good-sized  flat 
surface  is  shown,  and  see  how  the  medullary 
rays  are  here  represented  only  by  their 
edges. 

112.  Interruption  of  Annual  Rings  by 
Branches ;  Knots.  —  When  a  leaf -bud  is 
formed  on  the  trunk  or  branch  of  a 
dicotyledonous  tree,  it  is  connected  with 
the  wood  by  fibro- vascular  bundles.  As 
the  bud  develops  into  a  branch,  the  few 
bundles  which  it  originally  possessed 
increase  greatly  in  number,  and  at 
length,  as  the  branch  grows,  form  a 
cylinder  of  wood  which  cuts  across  the 
annual  rings,  as  shown  in  Fig.  74. 
This  interruption  to  the  rings  is  a  knot, 
such  as  one  often  sees  in  boards  and 
planks.  If  the  branch  dies  long  before 
the  tree  does,  the  knot  may  be  buried  under  many  rings 
of  wood.  What  is  known  as  clear  lumber  is  obtained 
from  trees  that  have  grown  in  a  dense  forest,  so  that  the 
lower  branches  of  the  larger  trees  were  killed  by  the  shade 
many  years  before  the  tree  was  felled. 

In  pruning  fruit  trees  or  shade  trees  the  branches 
which  are  removed  should  be  cut  close  to  the  trunk.  If 
this  is  done,  the  growth  of  the  trunk  will  bury  the  scar 
before  decay  sets  in. 


FIG.  74.  —  Formation  of 
a  Knot  in  a  Tree- 
Trunk. 

R,  cut-off  end  of  stick, 
showing  annual  rings ; 
K,  knot,  formed  by 
growth  of  a  branch. 


STRUCTURE   OF   THE   STEM 


103 


113.    Comparison  of  the  Monocotyledonous  and  the  Dicotyledonous 

Stem.1 

MONOCOTYLEDONOUS  DICOTYLEDONOUS 

STEM  STEM 


General  Structure. 


A  hard  rind  of 
rather  uniform  struc- 
ture. Bundles  inter- 
mixed with  the  pith. 


Structure  of 
Bundles. 

Growth  in  Thick- 
ness. 


Bundles  closed, 
that  is,  without  per- 
manent cambium. 

Cells  of  mature 
parts  of  stem  expand 
somewhat,  but  (in 
most  palms)  new  ones 
are  not  found. 


A  complex  bark, 
usually  on  young 
shoots  consisting  of 
a  corky  layer,  a  green 
layer,  and  a  layer  of 
bast.  Wood  in  an- 
nual rings.  Pith  in 
a  cylinder  at  the  cen- 
ter. 

Bundles  open,  with 
permanent  cambium. 


wood-cells 
formed  throughout 
growing  season  from 
cambium  ring. 


114.    Review  Sketches  and  Diagrams. 

(1)  Monocotyledonous  stem  (lengthwise  section). 

(2)  Dicotyledonous  stem  (lengthwise  section). 

(3)  First  appearance  of  bundles  in  dicotyledonous  stem. 

(4)  Dicotyledonous  stem  five  years  or  more  old  (cross-section). 

(5)  Various  bark-cells. 

(6)  Various  cells  from  wood. 

(7)  Pith-cells. 

(8)  Collenchy ma-cells. 


1  This  comparison  applies  only  to  most  of  the  woody  or  tree-like  stems. 


CHAPTER   VII 
LIVING   PARTS   OF   THE    STEM;    WORK   OF    THE    STEM 

115,  Active  Portions  of  the  Stems  of  Trees  and  Shrubs. 
—  In  annual  plants  generally  and  in  the  very  young 
shoots  of  shrubs  and  trees  there  are  stomata  or  breathing 
pores  which  occur  abundantly  in  the  epidermis,  serving 
for  the  admission  of  air  and  the  escape  of  moisture,  while 
the  green  layer  of  the  bark  answers  the  same  purpose  that 
is  served  by  the  green  pulp  of  the  leaf  (Chapter  XI). 
For  years,  too,  the  spongy  lenticels,  which  succeed  the 
stomata  and  occur  scattered  over  the  external  surface  of 
the  bark  of  trees  and  shrubs,  serve  to  admit  air  to  the 
interior  of  the  stem.  The  lenticels  at  first  appear  as 
roundish  spots,  of  very  small  size,  but  as  the  twig  or  shoot 
on  which  they  occur  increases  in  diameter  the  lenticel 
becomes  spread  out  at  right  angles  to  the  length  of  the 
stem,  so  that  it  sometimes  becomes  a  longer  transverse  slit 
or  scar  on  the  bark,  as  in  the  cherry  and  the  birch.  But 
in  the  trunk  of  a  large  tree  no  part  of  the  bark  except  the 
inner  layer  is  alive.  The  older  portions  of  the  bark,  such 
as  thS  highly  developed  cork  of  the  cork-oak,  from  which 
the  ordinary  stoppers  for  bottles  are  made,  sometimes 
cling  for  years  after  they  are  dead  and  useless  except  as  a 
protection  for  the  parts  beneath  against  mechanical  injuries 
or  against  cold.  But  in  many  cases,  as  in  the  shell-bark  hick- 
ory and  the  grapevine,  the  old  bark  soon  falls  off  in  strips ; 
in  birches  it  finally  peels  off  in  bands  around  the  stem. 

104 


LIVING   PARTS    OF   THE    STEM  105 

The  cambium  layer  is  very  much  alive,  and  so  is  the 
young  outer  portion  of  the  wood.  Testing  this  "sap- 
wood,"  particularly  in  winter,  shows  that  it  is  rich  in 
starch  and  proteids. 

The  heartwood  of  a  full-grown  tree  is  hardly  living, 
unless  the  cells  of  the  medullary  rays  retain  their  vitality, 
and  so  it  may  be  that  wood  of  this  kind  is  useful  to  the 
tree  mainly  by  giving  stiffness  to  the  trunk  and  larger 
branches,  thus  preventing  them  from  being  easily  broken 
by  storms. 

It  is,  therefore,  possible  for  a  tree  to  flourish,  sometimes 
for  centuries,  after  the  heartwood  has  much  of  it  rotted 
away  and  left  the  interior  of  the  trunk  hollow,  as  shown 
hi  Fig.  75. 

116,  Uses  of  the  Components  of  the  Stem.  —  There  is  a 
marked  division  of  labor  among  the  various  groups  of  cells 
that  make  up  the  stem  of  ordinary  dicotyledons,  particu- 
larly in  the  stems  of  trees,  and  it  will  be  best  to  explain 
the  uses  of  the  kinds  of  cells  as  found  in  trees,  rather  than 
in  herbaceous  plants.  A  few  of  the  ascertained  uses  of 
the  various  tissues  are  these: 

The  pith  forms  a  large  part  of  the  bulk  of  very  young 
shoots,  since  it  is  a  part  of  the  tissue  of  comparatively 
simple  structures  amid  which  the  nbro-vascular  bundles 
arise.  In  mature  stems  it  becomes  rather  unimportant, 
though  it  often  continues  for  a  long  time  to  act  as  a  store- 
house of  food. 

The  medullary  rays  in  the  young  shoot  serve  as  a  chan- 
nel for  the  transference  of  water  and  plant-food  in  a  liquid 
form  across  the  stem,  and  they  often  contain  much  stored 
food. 


106 


FOUNDATIONS   OF  BOTANY 


FIG.  75.  —  Pioneer's  Cabin,  a  Very  Large  Hollow  Sequoia. 

The   vessels    carry  water   upward   and  air   downward 
through  the  stem. 

The  wood-cells  of  the  heartwood  are  useful  only  to  give 


LIVING  PARTS   OF  THE   STEM  107 

stiffness  to  the  stem.  Those  of  the  sapwood,  in  addition 
to  this  work,  have  to  carry  meet  of  the  water  from  the 
roots  to  the  leaves  and  other  distant  portions  of  the  plant. 

The  cambium  layer  is  the  region  in  which  the  annual 
growth  of  the  tree  takes  place  (Figs.  69,  71). 

The  most  important  portion  of  the  inner  bark  is  that 
which  consists  of  sieve-tubes,  for  in  these  digested  and 
elaborated  plant-food  is  carried  from  the  leaves  toward  the 
roots. 

The  green  layer  of  the  bark  in  young  shoots  does  much 
toward  collecting  nutrient  substances,  or  raw  materials, 
and  preparing  the  food  of  the  plant  from  air  and  water, 
but  .this  work  may  be  best  explained  in  connection  with 
the  study  of  the  leaf  (Chapter  XI). 

117.  Movement  of  Water  in  the  Stem.  —  The  student 
has  already  learned  that  large  quantities  of  water  are  taken 
up  by  the  roots  of  plants. 

Having  become  somewhat  acquainted  with  the  structure 
of  the  stem,  he  is  now  in  a  position  to  investigate  the 
question  how  the  various  fluids,  commonly  known  as  sap, 
travel  about  in  it.1  It  is  important  to  notice  that  sap  is 
by  no  means  the  same  substance  everywhere  and  at  all 
times.  As  it  first  makes  its  way  by  osmotic  action  inward 
through  the  root-hairs  of  the  growing  plant  it  differs  but 
little  from  ordinary  spring  water  or  well  water.  The 
liquid  which  flows  from  the  cut  stem  of  a  "bleeding" 
grapevine  which  has  been  pruned  just  before  the  buds  have 
begun  to  burst  in  the  spring,  is  water  with  a  'little  muci- 
laginous or  slimy  material  added.  The  sap  which  is 

1  See  the  paper  on  "The  So-called  Sap  of  Trees  and  its  Movements,"  by 
Professor  Charles  R.  Barnes,  Science,  Vol.  XXI,  p.  535. 


108 


FOIL  IS    OF   EOT 


obtained  from  maple  trees"  .A  lat«  winter  or  early  spring, 
and  is  boiled  down  for  sy.-np  or  sugar,  is  still  richer  in 
nutritious  material  than  the  water  of  the  grapevine,  while 
the  elaborated  sap  which  is  sent  so  abundantly  into  the  ear 
of  corn,  at  its  period  of  filling  out,  or  into  the  growing 
pods  of  beans  and  peas,  or  into  the  rapidly  forming  acorn 
or  the  chestnut,  contains  great  stores  of  food,  suited  to  sus- 
tain plant  or  animal  life. 

EXPERIMENT   XXI 

Rise  of  Water  in  Stems.  —  Cut  some  short  branches  from  an 
apple  tree  or  a  cherry  tree  and  stand  the  lower  end  of  each 
in  red  ink;  try  the  same  experiment  with  twigs  of  oak,  ash, 
or  other  porous  wood,  and  after  some  hours1  examine  with 

the  magnifying  glass  and  with  the 
microscope,  using  the  2-inch  objective, 
successive  cross-sections  of  one  or  more 
twigs  of  each  kind.  Note  exactly  the 
portions  through  which  the  ink  has 
traveled.  Pull  off  the  leaves  from  one 
of  the  stems  after  standing  in  the  eosin 
solution,  and  notice  the  spots  on  the 
leaf-scar  through  which  the  eosin  has 
traveled.  These  spots  show  the  posi- 
tions of  the  leaf-traces,  or  fibre-vascular 
bundles,  connecting  the  stem  and  the 
leaf.  Repeat  with  several  potatoes,  cut 
crosswise  through  the  middle.  Try 
also  some  monocotyledonous  stems, 
such  as  those  of  the  lily  or  asparagus. 

For  the  sake  of  comparison  between 
FIG.  76.  —  A  Cutting  girdled  and  , 

sending  down  Roots  from  the     ™ots  and  stems,  treat  ^  any  convenient 

Upper  Edge  of  the  Girdled  King,     root,  such  as  a  parsnip,  in  the  same  way. 


1  If  the  twigs  are  leafy  and  the  room  is  warm,  only  from  5  to  30  minutes 
may  be  necessary. 


LIVING  PARTS   OF  THE   STEM 


109 


Examine  longitudinal  sections  o^  some  of  the  twigs,  the  potatoes, 
and  the  roots.  In  drawing  conclusions  about  the  channels  through 
which  the  ink  has  risen  (those  through  which  the  newly  absorbed 
soil-water  most  readily  trav- 
els), bear  in  mind  the  fact 
that  a  slow  soakage  of  the 
red  ink  will  take  place  in 
all  directions,  and  therefore 
pay  attention  only  to  the 
strongly  colored  spots  or 
lines. 

What  conclusions  can  be 
drawn  from  this  experiment 
as  to  the  course  followed  by 
the  sap? 


From  the  familiar 
facts  that  ordinary  for- 
est trees  apparently 
flourish  as  well  after  the 
almost  complete  decay 
and  removal  of  their 
heartwood,  and  that 
many  kinds  will  live 
and  grow  for  a  consider- 
able time  after  a  ring  of 
bark  extending  all  round 
the  trunk  has  been  re- 
moved, it  may  readily  be 
inferred  that  the  crude  sap  in  trees  must  rise  through  some 
portion  of  the  newer  layers  of  the  wood.  A  tree  girdled 
by  the  removal  of  a  ring  of  sapwood  promptly  dies. 

118.    Downward  Movement  of   Liquids.  —  Most  dicoty- 
ledonous stems,  when  stripped  of  a  ring  of  bark  and  then 


FIG.  77.  —  Channels  for  the  Movement  of 
Water,  upward  and  downward. 

The  heavy  black  lines  in  roots,  stems,  and 
leaves  show  the  course  of  the  fibro-vascular 
bundles  through  which  the  principal  move- 
ments of  water  take  place. 


110 


FOUNDATIONS   OF  BOTANY 


stood  in  water,  as  shown  in  Fig. 
bell-jar,  develop  roots  only  at  or 


FIG.  78.  —  Diagrammatic  Cross-Section  of  a 
Bundle  from  Sugar-Cane,  showing  Channels 
for  Air  and  Water.  (Magnified.) 

Air  travels  downward  through  the  two  large 
ducts  d  (and  the  two  smaller  ones  between 
them).  Water  travels  upward  through  the 
ducts  and  through  the  wood-cells  in  the 
region  marked  w.  Water  with  dissolved 
plant-food  travels  downward  through  the 
sieve-cells  in  the  region  marked  s. 


76,  and  covered  with  a 
near  the  upper  edge  of 
the  stripped  portion,1 
and  this  would  seem  to 
prove  that  such  stems 
send  their  building  ma- 
terial —  the  elaborated 
sap  —  largely  at  any  rate 
down  through  the  bark. 
Its  course  is  undoubt- 
edly for  the  most  part 
through  the  sieve-cells 
(Figs.  63,  64),  which  are 
admirably  adapted  to 
convey  liquids.  In  ad- 
dition to  these  general 
upward  and  downward 
movements  of  sap,  there 
must  be  local  transfers 


laterally  through  the  stem,  and 
these  are  at  times  of  much  im- 
portance to  the  plant. 

Since  the  liquid  building  mate- 
rial  travels    straight   down    the 

. ,  .  i          (,     . ,  FIG.  79.  —  Unequal  Growth  of  Kings 

Stem,    that    Side    O±    the    Stem    On      Of   Wood   in   nearly  Horizontal 
Which    the     manufacture    of    SUch      Stemof  a  Juniper.  (Natural  size.) 

material  is  going  on  most  rapidly  should  grow  fastest. 

1  This  may  be  made  the  subject  of  a  protracted  class-room  experiment. 
Strong  shoots  of  willow  should  be  used  for  the  purpose. 


LIVING  PARTS   OF   THE    STEM  111 

Plant-food  is  made  out  of  the  raw  materials  by  the  leaves, 
and  so  the  more  leafy  side  of  a  tree  forms  thicker  rings 
than  the  less  leafy  side,  as  shown  in  Fig.  79. 

119,  Rate  of  Movement  of  Water  in  the  Stem.  —  There 
are  many  practical  difficulties  in  the  way  of  ascertaining 
exactly  how  fast  the  watery  sap  travels  from  the  root  to 
the  leaves.  It  is,  however,  easy  to  illustrate  experimen- 
tally the  fact  that  it  does  rise,  and  to  give  an  approximate 
idea  of  the  time  required  for  its  ascent.  The  best  experi- 
ment for  beginners  is  one  which  deals  with  an  entire 
plant  under  natural  conditions. 

EXPERIMENT   XXII 

Wilting  and  Recovery.  —  Allow  a  fuchsia  or  a  hydrangea1  which 
is  growing  in  a  flower-pot  to  wilt  considerably  for  lack  of  watering. 
Then  water  it  freely  and  record  the  time  required  for  the  leaves  to 
begin  to  recover  their  natural  appearance  and  position,  and  the 
time  fully  to  recover. 

The  former  interval  of  time  will  give  a  very  rough  idea 
of  the  time  of  transfer  of  water  through  the  roots  and  the 
stem  of  the  plant.  From  this,  by  measuring  the  approxi- 
mate distance  traveled,  a  calculation  could  be  made  of  the 
number  of  inches  per  minute  that  water  travels  in  this 
particular  kind  of  plant,  through  a  route  which  is  partly 
roots,  partly  stem,  and  partly  petiole.  Still  another 
method  is  to  treat  leafy  stems  as  the  student  in  Exp.  XXI 
treated  the  twigs  which  he  was  examining,  and  note  care- 
fully the  rate  of  ascent  of  the  coloring  liquid.  This  plan 
is  likely  to  give  results  that  are  too  low,  still  it  is  of  some 
use.  It  has  given  results  varying  from  34  inches  per 

1  Hydrangea  hortensia. 


112  FOUNDATIONS  OF  BOTANY 

hour  for  the  willow  to  880  inches  per  hour  for  the  sun- 
flower. A  better  method  is  to  introduce  the  roots  of  the 
plant  which  is  being  experimented  upon  into  a  weak 
solution  of  some  chemical  substance  which  is  harmless  to 
the  plant  and  which  can  readily  be  detected  anywhere  in 
the  tissues  of  the  plant  by  chemical  tests.  Proper  tests 
are  then  applied  to  portions  of  the  stem  which  are  cut 
from  the  plant  at  short  intervals  of  time. 

Compounds  of  the  metal  lithium  are  well  adapted  for 
use  in  this  mode  of  experimentation. 

120.  Causes  of  Movements  of  Water  in  the  Stem.  —  Some 
of  the  phenomena  of  osmosis  were  explained  in  Sect.  62, 
and  the  work  of  the  root-hairs  was  described  as  due  to 
osmotic  action. 

Root-pressure  (Sect.  66),  being  apparently  able  to  sus- 
tain a  column  of  water  only  80  or  90  feet  high  at  the 
most,  and  usually  less  than  half  this  amount,  would  be 
quite  insufficient  to  raise  the  sap  to  the  tops  of  the  tallest 
trees,  since  many  kinds  grow  to  a  height  of  more  than  100 
feet.  Our  Californian  "  big  trees,"  or  Sequoias,  reach 
the  height  of  over  300  feet,  and  an  Australian  species  of 
Eucalyptus,  it  is  said,  sometimes  towers  up  to  470  feet. 
Root-pressure,  then,  may  serve  to  start  the  soil-water  on 
its  upward  journey,  but  some  other  force  or  forces  must 
step  in  to  carry  it  the  rest  of  the  way.  What  these  other 
forces  are  is  still  a  matter  of  discussion  among  botanists. 

The  slower  inward  and  downward  movement  of  the  sap 
may  be  explained  as  due  to  osmosis.  For  instance,  in  the 
case  of  growing  wood-cells,  sugary  sap  from  the  leaves 
gives  up  part  of  its  sugar  to  form  the  cellulose  of  which 
the  wood-cells  are  being  made. 


LIVING  PARTS  OF  THE   STEM  113 

This  loss  of  sugar  would  cause  a  flow  of  rather  watery 
sap  to  take  place  more  rapidly  than  usual  from  the  grow- 
ing wood  to  the  leaves,  while  at  the  same  time  a  slow 
transfer  of  the  dissolved  sugar  will  be  set  up  from  leaves 
to  wood.  The  water,  as  fast  as  it  reaches  the  leaves,  will 
be  thrown  off  in  the  form  of  vapor,  so  that  they  will 
not  become  distended  with  water,  while  the  sugar  will  be 
changed  into  cellulose  and  built  into  new  wood-cells  as  fast 
as  it  reaches  the  region  where  such  cells  are  being  formed. 

Plants  in  general l  readily  change  starch  to  sugar,  and 
sugar  to  starch.  When  they  are  depositing  starch  in  any 
part  of  the  root  or  stem  for  future  use,  the  withdrawal  of 
sugar  from  those  portions  of  the  sap  which  contain  it 
most  abundantly  gives  rise  to  a  slow  movement  of  dis- 
solved particles  of  sugar  in  the  direction  of  the  region 
where  starch  is  being  laid  up. 

121.  Storage  of  Food  in  the  Stem. — The  reason  why  the 
plant  may  profit  by  laying  up  a  food  supply  somewhere 
inside  its  tissues  has  already  been  suggested  (Sect.  91). 

The  most  remarkable  instance  of  storage  of  food  in  the 
stem  is  probably  that  of  sago-palms,  which  contain  an 
enormous  amount,  sometimes  as  much  as  800  pounds,  of 
starchy  material  in  a  single  trunk.  But  the  commoner 
plants  of  temperate  regions  furnish  plenty  of  examples  of 
deposits  of  food  in  the  stem.  As  in  the  case  of  seeds  and 
roots,  starch  constitutes  one  of  the  most  important  kinds 
of  this  reserve  material  of  the  stem,  and  since  it  is  easier 
to  detect  than  any  other  food  material  which  the  plant 
stores,  the  student  will  do  well  to  spend  time  in  looking 
for  starch  only. 

1  Not  including  most  of  the  flowerless  and  very  low  and  simple  kinds. 


114  FOUNDATIONS   OF  BOTANY 

Cut  thin  cross-sections  of  twigs  of  some  common  deciduous  tree 
or  shrub,  in  its  early  winter  condition,  moisten  with  iodine  solution, 
and  examine  for  starch  with  a  moderately  high  power  of  the  micro- 
scope. Sketch  the  section  with  a  pencil,  coloring  the  starchy  por- 
tions with  blue  ink,  used  with  a  mapping  pen,  and  describe  exactly 
in  what  portions  the  starch  is  deposited. 

122.  Storage  in  Underground  Stems.  —  The    branches 
and  trunk  of  a  tree  furnish  the  most  convenient  place 
in  which  to   deposit   food   during   winter  to  begin    the 
growth  of   the  following    spring.     But  in   those    plants 
which  die  down  to  the  ground  at  the  beginning  of  winter 
the    storage    must   be    either  in  the    roots,   as  has  been 
described   in   Sect.    58,   or   in   underground   portions    of 
the  stem. 

Rootstocks,  tubers,  and  bulbs  seem  to  have  been  de- 
veloped by  plants  to  answer  as  storehouses  through  the 
winter  (or  in  some  countries  through  the  dry  season)  for 
the  reserve  materials  which  the  plant  has  accumulated 
during  the  growing  season.  The  commonest  tuber  is  the 
potato,  and  this  fact  and  the  points  of  interest  which  it 
represents  make  it  especially  desirable  to  use  for  a  study 
of  the  underground  stem  in  a  form  most  highly  specialized 
for  the  storage  of  starch  and  other  valuable  products. 

123.  A  Typical  Tuber  :  the  Potato.  —  Sketch  the  general  outline 
of  a  potato,  showing  the  attachment  to  the  stem  from  which  it  grew.1 

Note  the  distribution  of  the  "eyes,"  —  are  they  opposite  or  alter- 
nate ?  Examine  them  closely  with  the  magnifying  glass  and  then  with 
the  lowest  power  of  the  microscope.  What  do  they  appear  to  be  ? 

If  the  potato  is  a  stem,  it  may  branch,  —  look  over  a  lot  of  pota- 
toes to  try  to  find  a  branching  specimen.  If  such  a  one  is  secured, 
sketch  it. 

1  Examination  of  a  lot  of  potatoes  will  usually  discover  specimens  with  an 
inch  or  more  of  attached  stem. 


LIVING   PARTS   OF   THE    STEM  115 

Note  the  little  scale  overhanging  the  edge  of  the  eye,  and  see  if 
you  can  ascertain  what  this  scale  represents. 

Cut  the  potato  across,  and  notice  the  faint  broken  line  which 
forms  a  sort  of  oval  figure  some  distance  inside  the  skin. 

Place  the  cut  surface  in  eosin  solution,  allow  the  potato  to  stand 
so  for  many  hours,  and  then  examine,  by  slicing  off  pieces  parallel 
to  the  cut  surface,  to  see  how  far  and  into  what  portions  the  solution 
has  penetrated.  Refer  to  the  notes  on  the  study  of  the  parsnip 
(Sect.  56),  and  see  how  far  the  behavior  of  the  potato  treated  with 
eosin  solution  agrees  with  that  of  the  parsnip  so  treated. 

Cut  a  thin  section  at  right  angles  to  the  skin,  and  examine  with  a 
high  power.  Moisten  the  section  with  iodine  solution  and  examine 
again. 

If  possible,  secure  a  potato  which  has  been  sprouting  in  a  warm 
place  for  a  month  or  more  (the  longer  the  better),  and  look  near 
the  origins  of  the  sprouts  for  evidences  of  the  loss  of  material  from 
the  tuber. 

EXPERIMENT   XXIII 

Use  of  the  Corky  Layer.  —  Carefully  weigh  a  potato,  then  pare 
another  larger  one,  and  cut  portions  from  it  until  its  weight  is  made 
approximately  equal  to  that  of  the  first  one.  Expose  both  freely  to 
the  air  for  some  days  and  reweigh.  What  does  the  result  show  in 
regard  to  the  use  of  the  corky  layer  of  the  skin? 

124,  Morphology  of  the  Potato.  —  It  is  evident  that  in 
the  potato  we  have  to  do  with  a  very  greatly  modified 
form  of  stem.  The  corky  layer  of  the  bark  is  well  repre- 
sented, and  the  loose  cellular  layer  beneath  is  very  greatly 
developed ;  wood  is  almost  lacking,  being  present  only  in 
the  very  narrow  ring  which  was  stained  by  the  red  ink, 
but  the  pith  is  greatly  developed  and  constitutes  the  prin- 
cipal bulk  of  the  tuber.  All  this  is  readily  understood  if 
we  consider  that  the  tuber,  buried  in  and  supported  by 
the  earth,  does  not  need  the  kinds  of  tissue,  which  give 


116  FOUNDATIONS   OF  BOTANY 

strength,  but  only  those  which  are  well  adapted  to  store 
the  requisite  amount  of  food. 

125,  Structure  of  a  Bulb  ;   the  Onion.  —  Examine  the  external 
appearance  of  the  onion  and  observe  the  thin  membranaceous  skin 
which  covers  it.     This  skin  consists  of  the  broad  sheathing  bases  of 
the  outer  leaves  which  grew  on  the  onion  plant  during  the  summer. 
Remove  these  and  notice  the  thick  scales  (also  formed  from  bases 
of  leaves  as  shown  in  Fig.  48)  which  make  up  the  substance  of  the 
bulb. 

Make  a  transverse  section  of  the  onion  at  about  the  middle  and 
sketch  the  rings  of  which  it  is  composed.  Cut  a  thin  section  from 
the  interior  of  the  bulb,  examine  with  a  moderate  power  of  the 
microscope,  and  note  the  thin-walled  cells  of  which  it  is  composed. 

Split  another  onion  from  top  to  bottom  and  try  to  find : 

(a)  The  plate  or  broad  flattened  stem  inside  at  the  base  (Fig.  47). 

(5)  The  central  bud. 

(c)  The  bulb-scales. 

(d)  In  some  onions  (particularly  large,  irregular  ones)  the  bulblets 
or  side  buds  arising  in  the  axes  of  the  scales  near  the  base. 

Test  the  cut  surface  for  starch. 

126.  Sugar  in  the  Onion. —  G-rape  sugar  is  an  important 
substance  among  those  stored  for  food  by  the  plant.     It 
received  its    name    from  the  fact   that   it   was    formerly 
obtained    for   chemical    examination    from   grapes.      Old 
dry  raisins  usually  show  little  masses  of  whitish  material 
scattered  over  the  skin  which  are  nearly  pure  grape  sugar. 
Commercially   it  is   now  manufactured   on   an   enormous 
scale  from  starch  by  boiling  with  diluted  sulphuric  acid. 
In  the  plant  it  is  made  from  starch  by  processes  as  yet 
imperfectly  understood,  and  another  sugar,  called  maltose, 
is  made  from  starch  in  the  seed  during  germination. 

Both  grape  sugar  and  maltose  (and  hardly  any  other 
substances)  have  the  power  of  producing  a  yellow  or 


LIVING  PARTS   OF   THE    STEM  117 

orange  color  and  throwing  down  an  orange  or  reddish 
deposit,  when  they  are  added  to  a  brilliant  blue  alkaline 
solution  of  copper,  known  as  FeJiling's  solution.1  The 
color  or  deposit  will  not  appear  until  the  solution  has 
been  heated,  to  boiling. 

EXPERIMENT  XXIV 

Testing  for  Grape  Sugar.  —  Heat  to  boiling  in  a  test-tube  or  a 
small  beaker  some  weak  syrup  of  grape  sugar  or  some  honey,  much 
diluted  with  water.  Add  Fehling's  solution,  a  few  drops  at  a  time, 
until  a  decided  orange  color  appears.  Repeat  the  test  with  the 
water  in  which  some  slices  of  onion  have  been  boiled,  filtering  the 
water  through  a  paper  filter  and  heating  again  to  boiling  before 
adding  the  test  solution.2 

127.  Proteids  in  the  Onion.  —  Since   the   onion   grows 
so  rapidly  on  being  planted  in  the  spring,  there  must  be 
a  large  supply  of  food  in  the  bulb ;  there  may  be  other 
substances  present  besides  sugar. 

EXPERIMENT  XXV 

• 
Testing  an   Onion   for  Other  Stored  Food.  —  Test  a  rather  thick 

slice  of  onion  by  heating  it  in  a  porcelain  evaporating  dish  with  a 
little  strong  nitric  acid  until  the  latter  begins  to  boil  and  the  onion 
becomes  somewhat  softened.8  Rinse  off  the  slice  of  onion  in  a  stream 
of  water,  then  pour  on  it  a  few  drops  of  ammonium  hydrate  and 
observe  any  change  of  color.  What  is  proved  ?  See  Sect.  29. 

128,  Tabular  Review  of  Experiments. 

[Continue  the  table  from  Sect.  74.] 

1  For  the  preparation  of  the  solution  see  Handbook. 

2  The  deposit  will  in  this  case,  even  if  orange  at  first,  finally  become  black, 
probably  owing  to  the  presence  of  sulphur  in  the  onion. 

3  Do  not  allow  the  acid  to  touch  the  clothing,  the  hands,  or  any  metallic 
object. 


118  FOUNDATIONS   OF  BOTANY 

129.    Review  Summary  of  Work  of  Stem. 

f  in  young  dicotyledonous  stems 
Channels  for  upward  movement  J  in   dicotyledonous    stems   several 

of  water  |       years  old 

I  in  monocotyledonous  stems 

Channels  for  downward  move-  f  in  dicotyledonous  stems       .     .     . 
ment  of  water  \  in  monocotyledonous  stems      .     . 


Channels  for  transverse  movements       . 

Rate  of  upward  movement 

C  where  stored 

Storage  of  plant-food  •<  kinds  stored 

louses      .     .     . 


CHAPTER    VIII 
BUDS 

130.  Structure  of  Buds.  —  While  studying  twigs  in  their 
winter  condition,  as  directed  in  Sects.  77,  78,  the  student 
had  occasion  to  notice  the  presence,  position,  and  arrange- 
ment of  buds  on  the  branch,  but  he  was  not  called  upon 
to  look  into  the  details  of  their  structure.    The  most  natu- 
ral time  to  do  this  is  just  before  the  "study  of  the  leaf  is 
begun,  since  leafy  stems  spring  from  buds,  and  the  rudi- 
ments of  leaves  in  some  form  must  be  found  in  buds. 

131.  The  Horse-Chestnut  Bud.  —  Examine  one  of  the  lateral  buds 
on  a  twig  in  its  winter  or  early  spring  condition.1 

Make  a  sketch  of  the  external  appearance  of  the  buds  as  seen  with 
a  magnifying  glass. 

How  do  the  scales  with  which  it  is 
covered  lie  with  reference  to  those 
beneath  them? 

Notice  the  sticky  coating  on  the  scales. 

Are  the  scales  opposite  or  alternate?        2~ 

Remove  the  scales  in  pairs,  placing 
them  in  order  on  a  sheet  of  paper,  thus  : 

Make  the  distance  from  1  to  1  as  much 
as  6  or  8  inches. 

How  many  pairs  are  found  ? 

Observe  as  the  scales  are  removed  whether  the  sticky  coating  is 

1  The  best  possible  time  for  this  examination  is  just  as  the  buds  are  begin- 
ning to  swell  slightly  in  the  spring.  The  bud  of  buckeye  or  of  cottonwood 
will  do  for  this  examination,  though  each  is  on  a  good  deal  smaller  scale  than 
the  horse-chestnut  bud.  Buds  may  be  forced  to  open  early  by  placing  twigs 
in  water  in  a  very  warm,  light  place  for  many  weeks. 

119 


120 


FOUNDATIONS   OF   BOTANY 


thicker  on  the  outside  or  the  inside  of  each  scale,  and  whether  it 
is  equally  abundant  on  all  the  successive  pairs. 
What  is  the  probable  use  of  this  coating  ? 

Note  the  delicate  veining  of  some  of  the  scales  as  seen  through 

the  magnifying  glass.     What  does 
this  mean? 

Inside  the  innermost  pair  are 
found  two  forked  woolly  objects ; 
what  are  these  ? 

Compare  with  Figs.  87  and  107. 
Their  shape  could  be  more  readily 
observed  if  the  woolly  coating  were 
removed. 

Can  you  suggest  a  use  for  the 
woolly  coating? 

Examine  a  terminal  bud  in  the 
same  way  in  which  you  have  just 
studied  the  lateral  bud. 

Does  it  contain  any  parts  not 
found  in  the  other? 

What  is  the  appearance  of  these 
parts  ? 

W'hat  do  they  represent  ? 
If  there  is  any  doubt  about  their 
nature,    study   them   further   on    a 
.  horse-chestnut  tree  during  and  im- 
mediately after  the  process  of  leaf- 
ing out  in  the  spring. 

For  comparison  study  at  least  one 
to  of  the  following  kinds  of  buds  in 
their  winter  or  early  spring  condi- 
tion :  hickory,  butternut,  beech,  ash,  magnolia  (or  tulip  tree),  lilac, 
balm  of  Gilead,  cottonwood,  cultivated  cherry.1 

1  Consult  the  account  of  the  mode  of  studying  buds  in  Professor  W.  F. 
Ganong's  Teaching  Botanist,  pp.  208-210.  If  some  of  the  buds  are  studied  at 
home,  pupils  will  have  a  better  chance  to  examine  at  leisure  the  unfolding 
process. 


FIG.  80.  —Dissected  Bud  of  Buckeye 
(^Esculus  macrostachya),  showing 
Transitions  from  Bud-Scales 
Leaves. 


BUDS 


121 


132.  Nature   of    Bud-Scales.  -  -  The 
fact  that  the  bud-seales  are  in  certain 
cases     merely     imperfectly    developed 
leaves    or   leaf-stalks    is    often    clearly 
manifest  from  the  series  of  steps  con- 
necting the  bud-scale  on  the  one  hand 
with  the  young  leaf  on  the  other,  which 
may  be  found  in  many  opening  buds, 
as   illustrated   by  Fig.   80.      In    other 
buds  the  scales  are  not  imperfect  leaves, 
but  the  little  appendages  (stipules,  Figs. 
98,  99)   which   occur  at  the   bases  of 
leaves.       This    kind    of    bud-scale    is 
especially  well  shown  in  the  magnolia 
and  the  tulip  tree. 

133.  Naked  Buds.  —  All  of  the  buds 
above  mentioned  are  winter  buds,  capa- 
ble of  living  through  the  colder  months 
of  the  year,  and  are  scaly  buds. 

In  the  herbs  of  temperate  climates, 
and  even  in  shrubs  and  trees  of  tropical 
regions,  the  buds  are  often  naked,  that 
is,  nearly  or  quite  destitute  of  scaly 
coverings  (Fig.  81). 

Make  a  study  of  the  naked  buds  of  any 
convenient  herb,  such  as  one  of  the  common 
"  geraniums  "  (Pelargonium),  and  record  what 
you  find  in  it. 


134.    Position   of   Buds.  —  The    dis-  FlG- 81>  ~ Tip  of  Branch 

of  Ailanthus  in  Winter 

tinction  between   lateral   and   terminal    condition,  showing 

very  Large  Leaf-Scars 
and  nearly  Naked  Buds. 


buds  has  already  been  alluded  to. 


122 


FOUNDATIONS   OF   BOTANY 


The  plumule  is  the  first  terminal  bud  which  the  plant 
produces.  Lateral  buds  are  usually  axillary,  as  shown  in 
Fig.  82,  that  is,  they  grow  in  the  angle  formed  by  the 
leaf  with  the  stem  (Latin  axilla,  armpit).  But  not  infre- 
quently there  are  several  buds  grouped  in  some  way  about 


PIG.  82.- 


Alternate  Leaves  of  Cultivated  Cherry,  with  Buds  in 
their  Axils,  in  October. 


a  single  leaf -axil,  either  one  above  the  other,  as  in  the 
butternut  (Fig.  84),  or  grouped  side  by  side,  as  in  the  red 
maple,  the  cherry,  and  the  box-elder  (Fig.  83). 

In  these  cases  all  the  buds  except  the  axillary  one  are 
called  accessory  or  supernumerary  buds. 

135.  Leaf-Buds  and  Flower-Buds ;  the  Bud  an  Undevel- 
oped Branch.  —  Such  buds  as  the  student  has  so  far 


BUDS 


123 


examined  for  himself  are  not  large  enough  to  show  in  the 
most  obvious  way  the  relation  of  the  parts  and  their  real 
nature. 

Fortunately,  it  is  easy  to  obtain  a  gigantic  terminal  bud 
which  illustrates  perfectly  the  structure  and  arrangement 
of   the    parts    of   buds    in 
general. 

Examine  and  sketch  a  rather 
small,  firm  cabbage,  preferably 
a  red  one,  which  has  been  split 
lengthwise  through  the  center 1 
and  note 

(a)  The  short,  thick,  conical 
stem. 

(&)  The  crowded  leaves 
which  arise  from  the  stem,  the 
lower  and  outer  ones  largest 
and  most  mature,  the  upper 
and  innermost  ones  the  small- 
est of  the  series. 

(c)  The  axillary  buds,  found 
in  the  angles  made  by  some 
leaves  with  the  stem. 

Compare  the  section  of  the  cabbage  -with  Fig.  86. 

Most  of  the  buds  so  far  considered  were  leaf-buds,  that 
is,  the  parts  inside  of  the  scales  would  develop  into  leaves, 
and  their  central  axes  into  stems  ;  but  some  were  mixed 
buds,  that  is,  they  contained  both  leaves  and  flowers  in  an 
undeveloped  condition. 

Flower-buds  contain  the  rudiments  of  flowers  only. 

Sometimes,  as  in  the  black  walnut  and  the  butternut, 
the  leaf-buds  and  flower-buds  are  readily  distinguishable 

1  Half  of  a  cabbage  will  be  enough  for  the  entire  division. 


FIG.  83.  —Accessory  Buds  of  Box-Elder 
(Negundo).    (Magnified.) 

A,  front  view  of  group. 

.B,  two  groups  seen  in  profile. 


124 


FOUNDATIONS   OF  BOTANY 


by  their  difference  in  form,  while  in  other  cases,  as  in  the 
cultivated  cherry,  the  difference  in  form  is  but  slight. 
The  rings  of  scars  about  the  twig,  shown  in  Figs.  82 
and  85,  mark  the  place  where  the  bases 
of  bud-scales  were  attached.  A  little 
examination  of  the  part  of  the  twig 
which  lies  outside  of  this  ring,  as  shown 
in  Fig.  82,  will  lead  one  to  the  conclu- 
sion that  this  portion  has  all  grown  in 
the  one  spring  and  summer  since  the 
bud-scales  of  that  particular  ring  dropped 
off.  Following  out  this  suggestion,  it  is 
easy  to  reckon  the  age  of  any  moder- 
ately old  portion  of  a  branch,  since  it  is 
equal  to  the  number  of  segments  between 
the  rings.  In  rapidly  growing  shoots  of 
willow,  poplar,  and  similar  trees,  5  or  10 
feet  of  the  length  may  be  the  growth  of 
a  single  year,  while  in  the  lateral  twigs 
of  the  hickory,  apple,  or  cherry  the  yearly 
increase  may  be  but  a  fraction  of  an  inch. 
Such  fruiting  "  spurs  "  as  are  shown  in 
Fig.  85  are  of  little  use  in  the  permanent 

gr°wth  °f  the  tree'  and  p°plars'  elms> 

soft   maples    and   other   trees  shed   the 

I  leaf-scar  ;«*,  axil-        w      t      f    th  Whatever 

lary  bud  ;  a,  a,  ac-  *•     J 

the  amount  of  this  growth,  it  is  but  the 
lengthening  out  and  development  of  the 
bud,  which  may  be  regarded  as  an  undeveloped  stem  or 
branch,  with  its  intern-odes  so  shortened  that  successive 
leaves  seem  almost  to  spring  from  the  same  point. 


a. 


(Reduced.) 


cessory  buds ; 
terminal  bud. 


BUDS 


125 


136.  Vernation.  —  Procure  a  considerable  number  of  buds  which 
are  just  about  to  burst,  and  others  which  have  begun  to  open.  Cut 
each  across  with  a  razor  or  very  sharp  scalpel ;  examine  first  with 
the  magnifying  glass,  and  then  with  the  lowest  power  of  the  micro- 
scope. Pick  to  pieces  other  buds  of  the  same 
kinds  under  the  magnifying  glass,  and  report 
upon  the  manner  in  which  the  leaves  are 
packed  away. 

The  arrangement  of  leaves  in  the 
bud  is  called  vernation;  some  of  the 

principal  modes  are  shown  in  Fig.  86. 

f...     sc 


-1900 
-—1899 

ax__ 


FIG.  85.  —A  slowly  grown  Twig 
of  Cherry,  3  inches  long  and 
about  ten  years  old. 

The  pointed  bud  I  is  a  leaf -bud ; 
the  more  obtuse  accessory 
buds  /,  /  are  flower-buds. 


FIG.  86. 

J5,  a  twig  of  European  elm  ;  A,  a  longitudi- 
nal section  of  the  buds  of  B  (considerably 
magnified) ;  ax,  the  axis  of  the  bud,  which 
will  elongate  into  a  shoot ;  sc,  leaf-scars. 


In  the  cherry  the  two  halves  of  the  leaf  are  folded 
together  flat,  with  the  under  surfaces  outward  ;  in  the 
walnut  the  separate  leaflets,  or  parts  of  the  leaf,  are  folded 


126 


FOUNDATIONS   OF   BOTANY 


flat  and  then  grouped  into  a  sort  of  cone  ;  in  the  snow- 
ball each  half  of  the  leaf  is  plaited  in  a  somewhat  fan-like 
manner,  and  the  edges  of  the  two  halves  are  then  brought 
round  so  as  to  meet;  in  the  lady's  mantle  the  fan-like 
plaiting  is  very  distinct ;  in  the  wood  sorrel  each  leaflet 


FIG.  87, 1.  — Types  of  Vernation. 
1,  2,  Cherry  ;  3,  4,  European  walnut ;  5,  6,  snowball ;  7,  lady's  mantle  ;  8,  oxalis. 

is  folded  smoothly,  and  then  the  three  leaflets  packed 
closely  side  by  side.  All  these  modes  of  vernation  and 
many  others  have  received  accurate  descriptive  names  by 
which  they  are  known  to  botanists. 

137.    Importance  of  Vernation.  — The  significance  of  ver- 
nation is  best  understood  by  considering  that  there  are  two 


BUDS  127 

important  purposes  to  be  served ;  the  leaves  must  be 
stowed  as  closely  as  possible  in  the  bud,  and  upon  begin- 
ning to  open  they  must  be  protected  from  too  great  heat 
and  dryness  until  they  have  reached  a  certain  degree  of 
firmness.  It  may  be  inferred  from  Fig.  87,  I,  that  it  is 
common  for  very  young  leaves  to  stand  vertically.  This 
protects  them  considerably  from  the  scorching  effect  of  the 
sun  at  the  hottest  part  of  the  day.  Many  young  leaves, 
as,  for  instance,  those  of  the  silver-leafed  poplar,  the  pear, 
the  beech,  and  the  mountain  ash,  are  sheltered  and  pro- 


FIG.  87,  II.  —  Development  of  an  Oxalis  Leaf. 

A,  full-grown  leaf ;  B,  rudimentary  leaf,  the  leaflets  not  yet  evident ;  C,  more 
advanced  stage,  the  leaflets  appearing ;  D,  a  still  more  advanced  stage  ; 
B,  C,  and  Z>,  considerably  magnified. 

tected  from  the  attacks  of  small  insects  by  a  coating  of 
wool  or  down,  which  they  afterwards  lose.  Those  of  the 
tulip  tree  are  enclosed  for  a  little  time  in  thin  pouches, 
which  serve  as  bud-scales,  and  thus  entirely  shielded  from 
direct  contact  with  the  outside  air  (see  Sect.  117). 

138.  Dormant  Buds.  —  Generally  some  of  the  buds  on  a 
branch  remain  undeveloped  in  the  spring,  when  the  other 
buds  are  beginning  to  grow,  and  this  inactive  condition 
may  last  for  many  seasons.  Finally  the  bud  may  die,  or 
some  injury  to  the  tree  may  destroy  so  many  other  buds 
as  to  leave  the  dormant  ones  an  extra  supply  of  food,  and 


128  FOUNDATIONS   OF  BOTANY 

this,  with  other  causes,  may  force  them  to  develop  and  to 
grow  into  branches. 

Sometimes  the  tree  altogether  fails  to  produce  buds  at 
places  where  they  would  regularly  occur.  In  the  lilac  the 
terminal  bud  usually  fails  to  appear,  and  the  result  is  con- 
stant forking  of  the  branches. 

139.  Adventitious  Buds.  —  Buds  which  occur  in  irregu- 
lar places,  that  is,  not  terminal  nor  in  or  near  the  axils  of 
leaves,  are  called  adventitious  buds  ;  they  may  spring  from 
the  roots,  as  in  the  silver-leafed  poplar,  or  from  the  sides 
of  the  trunk,  as  in  our  American  elm.  In  many  trees,  for 
instance  willows  and  maples,  they  are  sure  to  appear  after 
the  trees  have  been  cut  back.  Willows  are  thus  cut  back 
or  pollarded,  as  shown  in  Plate  II,  in  order  to  cause  them 
to  produce  a  large  crop  of  slender  twigs  suitable  for 
basket-making. 

Leaves  rarely  produce  buds,  but  a  few  kinds  do  so  when 
they  are  injured.  Those  of  the  bryophyllum,  a  plant  allied 
to  the  garden  live-for-ever,  when  they  are  removed  from 
the  plant  while  they  are  still  green  and  fresh,  almost  always 
send  out  buds  from  the  margin.  These  do  not  appear  at 
random  but  are  borne  at  the  notches  in  the  leaf-margin  and 
are  accompanied  almost  from  the  first  by  minute  roots. 

Pin  up  a  bryophyllum  leaf  on  the  wall  of  the  room  or 
lay  it  on  the  surface  of  moist  earth,  and  follow,  day  by  day, 
the  formation  and  development  of  the  buds  which  it  may 
produce. 

This  plant  seems  to  rely  largely  upon  leaf-budding  to 
reproduce  itself,  for  in  a  moderately  cool  climate  it  rarely 
flowers  or  seeds,  but  drops  its  living  leaves  freely,  and  from 
each  such  leaf  one  or  several  new  plants  may  be  produced. 


PLATE  II.  _  Pollarded  Willows 


BUDS  129 

140.    Review  Summary  of  Chapter  VIII. 

Coverings  .     .     .  -- -V  - 

leaf-buds 


Contents    .     .     J  flower-buds 
I  mixed  buds 


regular 

Classes  of  buds  as  re- 
position    .     . 

irregular 


Make  a  sketch  of  Fig.  82  as  it  looked  in  June  of  the  same  sum- 
mer ;    also  as  it  would  look  the  following  June. 


CHAPTER    IX 
LEAVES 

141.  The  Elm  Leaf.  —  Sketch  the  leafy  twig  of  elm  that  is  sup- 
plied to  you.1 

Report  on  the  following  points  : 
(a)  How  many  rows  of  leaves  ? 

(5)  How  much  overlapping  of  leaves  when  the  twig  is  held  with 
the  upper  sides  of  the  leaves  toward  you  ?    Can  you  suggest  a  reason 
for  this  ?     Are  the  spaces  between  the  edges  of  the  leaves  large  or 
small  compared  with  the  leaves  themselves  ? 

Pull  off  a  single  leaf  and  make  a  very  careful  sketch  of  its  under 
surface,  about  natural  size.    Label  the  broad  expanded  part  the  blade, 
and  the  stalk  by  which  it  is  attached  to  the  twig,  leaf-stalk  or  petiole. 
Study  the  outline  of  the  leaf  and  answer  these  questions : 
(a)  What  is  the  shape  of  the  leaf  taken  as  a  whole  ?     (See  Fig. 
88.)     Is  the  leaf  bilaterally  symmetrical,  i.e.,  is  there  a  middle  line 
running  through  it  lengthwise,  along  which  it  could  be  so  folded 
that  the  two  sides  would  precisely  coincide  ? 

(6)  What  is  the  shape  of  the  tip  of  the  leaf?     (See  Fig.  89.) 
(c)  Shape  of  the  base  of  the  leaf?     (See  Fig.  90.) 

(rf)  Outline  of  the  margin  of  the  leaf?     (See  Fig.  93.) 
Notice  that  the  leaf  is  traversed  lengthwise  by  a  strong  midrib 
and  that  many  so-called  veins  run  from  this  to  the  margin.     Are 

1  Any  elm  will  answer  the  purpose.  Young  strong  shoots  which  extend 
horizontally  are  best,  since  in  these  leaves  are  most  fully  developed  and  their 
distribution  along  the  twig  appears  most  clearly.  Other  good  kinds  of  leaves 
with  which  to  begin  the  study,  if  elm  leaves  are  not  available,  are  those  of 
beech,  oak,  willow,  peach,  cherry,  apple.  Most  of  the  statements  and  direc- 
tions above  given  would  apply  to  any  of  the  leaves  just  enumerated.  If  this 
chapter  is  reached  too  early  in  the  season  to  admit  of  suitable  material  being 
procured  for  the  study  of  leaf  arrangement,  that  topic  may  be  omitted  until 
the  leaves  of  forest  trees  have  sufficiently  matured. 

130 


LEAVES 


131 


FIG.  88.  —  General  Outline  of  Leaves. 

a,  linear ;  6,  lanceolate  ;  c,  wedge-shaped ;  d,  spatulate  ;  e,  ovate  ;  /,  obovate  ; 
g,  kidney-shaped ;  h,  orbicular  ;  i,  elliptical. 


/  9 

FIG.  89.— Tips  of  Leaves. 

a,  acuminate  or  taper-pointed ;  b,  acute  ;  c,  obtuse  ;  d,  truncate  ;  e,  retuse ;  /, 
emarginate  or  notched  ;  g  (end  leaflet),  obcordate  ;  h,  cuspidate,  — the  point 
sharp  and  rigid  ;  i,  mucronate, —the point  merely  a  prolongation  of  the  midrib. 


132 


FOUNDATIONS   OF  BOTANY 


FIG.  90.  —  Shapes  of  Bases  of  Leaves. 


1,  heart-shaped  (unsymmetrically) ;  2,  arrow- 
shaped  ;  3,  halberd-shaped. 


FIG.  91.  —  Peltate  Leaf  of 
Tropaeolum. 


FIG.  92. 

A;  runcinate  leaf  of  dandelion  ;  B, 
lyrate  leaf. 


FIG.  93.  —  Shapes  of  Margins 

of  Leaves. 

a  (1),  finely  serrate  ;  (2),  coarsely 
serrate ;  (3),  doubly  serrate. 
6  (1),  finely  dentate  ;  (2) ,  sinuate 
dentate ;  (3),  doubly  dentate. 
c,  deeply  sinuate,  d,  wavy. 
e  (1),  crenate  or  scalloped  ;  (2), 
doubly  crenate. 


LEAVES 


133 


these  veins  parallel  ?  Hold  the  leaf  up  towards  the  light  and  see 
how  the  main  veins  are  connected  by  smaller  ueinlets.  Examine 
with  your  glass  the  leaf  as  held  to  the  light 
and  make  a  careful  sketch  of  portions  of 
one  or  two  veins  and  the  intersecting  vein- 
lets.  How  is  the  course  of  the  veins  shown 
on  the  upper  surface  of  the  leaf  ? 

Examine  both  surfaces  of  the  leaf  with 
the  glass  and  look  for  hairs  distributed  on 
the  surfaces.  Describe  the  manner  in  which 
the  hairs  are  arranged. 


FIG.  94.— Netted  Vein- 
ing  (pinnate)  in  the 
Leaf  of  the  Foxglove. 


The  various  forms  of  leaves  are 
classed  and  described  by  botanists  with 
great  minuteness,1  not  simply  for  the 
study  of  leaves  themselves,  but  also 
because  in  classifying  and  describing 
plants  the  characteristic  forms  of  the 
leaves  of  many  kinds  of  plants  form 
a  very  simple 
and  ready 

means    of    distinguishing    them 

from  each  other  and  identifying 

them.     The  student  is  not  ex- 
pected to  learn  the  names  of  the 

several   shapes   of   leaves    as   a 

whole  or  of  their  bases,  tips,  or 

margins,  except  in  those   cases 

in  which  he   needs  to  use  and 

apply  them. 

Many  of  the  words  used  to  describe  the  shapes  of  leaves 

are  equally  applicable  to  the  leaf-like  parts  of  flowers. 


FIG.  95.  —  jetted  Veining  (pal- 
mate) in  Leaf  of  Melon. 


See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  pp.  623-637. 


134 


FOUNDATIONS   OF  BOTANY 


142.    The  Maple  Leaf.  —  Sketch  the  leafy  twig. 
Are  the  leaves  arranged  in  rows  like  those  of  the  elm  ?     How  are 
they  arranged  ? 

How  are  the  petioles  distorted  from  their  natural  positions  to 
bring  the  proper  surface  of  the  leaf  upward  toward  the  light  ? 

Do  the  edges  of  these  leaves  show  larger  spaces  between  them 
than  the  elm  leaves  did,  i.e.,  would  a  spray  of  maple  intercept  the 
sunlight  more  or  less  perfectly  than  a  spray  of 
elm  ?     Pull  off  a  single  leaf  and  sketch  its  lower 
surface,  about  natural  size. 

Of  the  two  main   parts  whose  names  have 
already  been  learned  (blade  and  petiole),  which 
is  more  developed  in  the  maple   than  in   the 
elm  leaf? 
Describe : 

(a)  The  shape  of  the  maple  leaf  as  a  whole. 
To  settle  this,  place  the  leaf  on  paper,  mark  the 
positions  of  the  extreme  points  and  connect 
these  by  a  smooth  line. 

(&)  Its  outline  as  to  main  divisions :  of  what 
The  blade  of  the  leaf  is    kind  and  how  many. 

(c)  The    detailed    outline    of     the    margin 


FIG.  96.  —  Pinnately 
Divided  Leaf  of 
Celandine. 


discontinuous,  con- 
sisting of  several  por- 
tions between  which 
are  spaces  in  which 
one  part  of  the  blade 
has  been  developed. 


,-p,. 

\ 


Compare  the  mode  of  veining  or  venation  of 
the    elm    and    the    maple    leaf    by   making    a 
diagram  of  each. 
These  leaves  agree  in  being  netted-veined ;  i.e.,  in  having  veinlets 
that  join  each  other  at  many  angles,  so  as  to  form  a  sort  of  delicate 
lace-work,  like  Figs.  94  and  95. 

They  differ,  however,  in  the  arrangement  of  the  principal  veins.  Such 

a  leaf  as  that  of  the  elm  is  said  to  be  feather-veined,  orpinnately  veined. 

The  maple  leaf,  or  any  leaf  with  closely  similar  venation,  is  said  to 

be  palmately  veined.     Describe  the  difference  between  the  two  plans 

of  venation. 

143,   Relation  of  Venation  to  Shape  of  Leaves.  — As  soon 
as  the  student  begins  to  observe  leaves  somewhat  widely, 


LEAVES 


135 


he  can  hardly  fail  to  notice  that  there  is  a  general  relation 
between  the  plan  of  venation  and  the  shape  of  the  leaf. 
How  may  this  relation  be  stated?  In  most  cases  the 
principal  veins  follow  at  the  outset  a  pretty  straight 
course,  a  fact  for  which  the  student  ought  to  be  able  to 
give  a  reason  after  he  has  performed  Exp.  XXXII. 

On  the  whole,  the  arrangement  of  the 
veins  seems  to  be 
such  as  to  stiff- 
en the  leaf 
most  in  the 
parts  that  need 


FIG.  97.  —  Palmately  Divided 
Leaf  of  Buttercup. 


FIG.  98.  — Leaf  of  Ap- 
ple, with  Stipules. 


PIG.  99.  —  Leaf  of 
Pansy,  with  Leaf- 
Like  Stipules. 


most  support,  and  to  reach  the  region  near  the  margin  by 
as  short  a  course  as  possible  from  the  end  of  the  petiole. 

144,  Stipules.  —  Although  they  are  absent  from  many 
leaves,  and  disappear  early  from  others,  stipules  form  a 
part  of  what  the  botanist  regards  as  an  ideal  or  model 
leaf.1  When  present  they  are  sometimes  found  as  little 

1  Unless  the  elm  twigs  used  in  the  previous  study  were  cut  soon  after  the 
unfolding  of  the  leaves  in  spring,  the  stipules  may  not  have  been  left  in  any 
recognizable  shape. 


136 


FOUNDATIONS   OF  BOTANY 


PIG.  100.  —  Parallel- 
Veined  Leaf  of  Sol- 
omon's Seal. 


bristle^haped  objects  at  the  base  of  the  leaf,  as  in  the 
apple  leaf  (Fig.    98),   sometimes  as  leaf-like   bodies,  for 
JL  example  in  the  pansy  (Fig.  99),  and  in 

y^^Wllwk       many  other  forms,  one  of  which  is  that 
/«Illlllffllm     of  sPinous  appendages,  as  shown  in  the 
common  locust  (Fig.  103). 

145.  Parallel -Veined  Leaves.  —  The 
leaves  of  many  great  groups  of  plants, 
such  as  the  lilies,  the  sedges,  and  the 
grasses,  are  commonly  parallel-veined, 
that  is,  with  the  veins  running  nearly 
parallel,  lengthwise  through  the  blade, 
as  shown  in  Fig.  100,  or 
with  parallel  veins  pro- 
ceeding from  a  midrib  and  thence  extend- 
ing to  the  margin,  as  shown  in  Fig.  101. 
146.  Occurrence  of  Netted  Veining  and 
of  Parallel  Veining.  —  The  student  has 
already,  in  his  experiments  on  germina- 
tion, had  an  opportunity  to  observe  the 
difference  in  mode  of  veining  between 
the  leaves  of  some  dicotyledonous  plants 
and  those  of  monocotyledonous  plants. 
This  difference  is  general  throughout 
these  great  groups  of  flowering  plants. 
What  is  the  difference? 

The  polycotyledonous  pines,   spruces,   FIG.  101.  —  Parallel 
and   other   coniferous  trees   have  leaves     £ffiL££££ 
with  but  a  single  vein,  or  two  or  three     midrib  to  margin- 
parallel  ones,  but  in  their  case  the  veining  could  hardly 
be  other  than  parallel,  since  the  needle-like  leaves  are  so 


LEAVES 


13T 


narrow  that  no  veins  of  any  considerable  length  could 
exist  except  in  a  position  lengthwise  of  the  leaf. 

The  fact  that  a  certain  plan  of  venation  is  found  mainly 
in  plants  with  a  particular  mode  of  germination,  of  stem 
structure,  and  of  arrangement  of  floral  parts,  is  but  one 
of  the  frequent 
cases  in  botany 
in  which  the 
structures  of 
plants  are  corre- 
lated in  a  way 
which  it  is  not 
easy  to  explain. 

No  one  knows 
why  plants  with 
two  cotyledons 
should  have 
n  e  1 1  e  d- v  e  i  n  e  d 
leaves,  but  many 
such  facts  as  this 
are  familiar  to 
every  botanist. 

147.  Simple 
and  Compound 
•Leaves.  —  The 
leaves  so  far  studied  are  simple  leaves,  that  is,  leaves  of  which 
the  blades  are  more  or  less  entirely  united  into  one  piece. 
But  while  in  the  elm  the  margin  is  cut  in  only  a  little 
way,  in  some  maples  it  is  deeply  cut  in  toward  the  bases 
of  the  veins.  In  some  leaves  the  gaps  between  the 
adjacent  portions  extend  all  the  way  down  to  the  petiole 


FIG.  102.  —  The  Fall  of  the  Horse-Chestnut  Leaf. 


138 


FOUNDATIONS   OF   BOTANY 


(in  palmately  veined  leaves)  or  to  the  midrib  (in  pinnately 
veined  ones).  Such  divided  leaves  are  shown  in  Figs. 
96  and  97. 

In  still  other  leaves,  known  as  compound  leaves,  the 
petiole,  as  shown  in  Fig.  102  (palmately  compound),  or  the 
midrib,  as  shown  in  Fig.  103  (pin- 
nately compound),  bears  what  look  to 
be  separate  leaves.  These  differ  in 
their  nature  and 
mode  of  origin 
from  the  portions 
of  the  blade  of  a 
divided  leaf.  One 
result  of  this  dif- 
ference appears  in 
the  fact  that  some 
time  before  the 
whole  leaf  is  ready 
to  fall  from  the 
tree  or  other  plant 
in  autumn,  the 
separate  portions 
or  leaflets  of  a 
compound  leaf  are 
seen  to  be  jointed- 
at  their  attach- 
ments, just  as  whole  leaves  are  to  the  part  of  the  stem  from 
which  they  grow.  In  Fig.  102  the  horse-chestnut  leaf  is 
shown  at  the  time  of  falling,  with  some  of  the  leaflets 
already  disjointed. 

That  a  compound  leaf,  in  spite  of  the  joints   of  the 


FlG.  103.  — Pinnately  Com- 
pound Leaf  of  Locust, 
with  Spines  for  Stipules. 


FIG.  104. —  Pinnately 
Compound  Leaf  of 
Pea.  A  tendril  takes 
the  place  of  a  terminal 
leaflet. 


LEAVES  139 

separate  leaflets,  is  really  only  one  leaf  is  shown  :   (1)  by 
the  absence  of  buds  in  the  axils  of  leaflets  (see  Fig.  82)  ; 

(2)  by  the  arrangement  of  the  blades  of  the  leaflets  hori- 
zontally, without  any  twist  in  their  individual  leaf-stalks  ; 

(3)  by  the  fact  that  their  arrangement  on  the  midrib  does 
not  follow  any  of  the  systems  of  leaf  arrangement  on  the 
stem  (Sect.  149).     If  each  leaflet  of  a  compound  leaf  should 
itself  become  compound,  the  result  would  be  to  produce 
a  twice  compound  leaf.     Fig.  113  shows  that  of  an  acacia. 
What  would  be  the  appearance  of  a  thrice  compound  leaf? 

148,    Review  Summary  of  Leaves.1 

f1- 

Parts  of  a  model  leaf      ...  . Jo 


Classes  of  netted-veined  leaves 


Classes  of  parallel-veined  leaves 


Relation  of  venation  to  number  of  cotyledons     .     .     .     .     J 

Compound  leaves ;  — types,  dependent  on  arrangement  of       II. 
leaflets |  2. 


Once,  twice,  or  three  times  compound  .... 
1  Illustrate  by  sketches  if  possible. 


CHAPTER   X 


LEAF  ARRANGEMENT  FOR  EXPOSURE  TO  SUN  AND  AIR; 
MOVEMENTS   OF  LEAVES  AND   SHOOTS 

149.    Leaf  Arrangement.1  —  As  has  been  learned  from 
the  study  of  the  leafy  twigs  examined,  leaves  are  quite 

generally  arranged  so  as  to 
secure  the  best  possible  ex- 
posure to  the  sun  and  air. 
This,  in  the  vertical  shoots 
of  the  elm,  the  oak  (Fig.  105), 
^e  aPPle>  beech,  and  other 
alternate-leaved  trees,  is  not 
inconsistent  with  their  spiral 
arrangement  of  the  leaves 


FIG.  105.  —  Leaf  Arrangement 
of  the  Oak. 


around  the  stem.  In  horizon- 
tal twigs  and  branches  of  the 
elm,  the  beech  (Fig.  106), 
the  chestnut,  the  linden,  and 
many  other  trees  and  shrubs, 
the  desired  effect  is  secured 
by  the  arrangement  of  all  the 
leaves  in  two  flat  rows,  one  on  each  side  of  the  twig. 


FIG.  106.  —  Leaf  Arrangement  of 
European  Beech. 


1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  pp.  396-424. 

140 


PLATE  III.  —  Exposure  to  Sunlight,  Japanese  Ivy 


LEAF  EXPOSURE  TO  SUN  AND  AIR 


141 


FIG.  107.— Leaf  Arrangement  of  Horse-Chestnut  on 
Vertical  Shoots  (top  view). 


The  rows  are  produced,  as  it  is  easy  to  see  on  examining 
such  a  leafy  twig,  by  a  twisting  about  of  the  petioles. 

The  adjustment 
A 

<mjj,  in  many  opposite- 

leaved  trees  and 
shrubs  consists  in 
having  each  pair 
of  leaves  cover 
the  spaces  be- 
tween the  pair 
below  it,  and 
sometimes  in  the 
lengthening  of 
the  lower  petioles 
so  as  to  bring 
the  blades  of 
the  lower  leaves  outside  those  of  the  upper  leaves.  Ex- 
amination of  Figs.  107  and  108  will  make  the  matter 
clear. 

The  student 
should  not  fail  to 
study  the  leafage 
of  several  trees  of 
different  kinds  on 
the  growing  tree 
itself,  and  in 
climbers  on  walls 
(Plate  III),  and  to 
notice  how  circum- 
stances modify  the  position  of  the  leaves.  Maple  leaves,  for 
example,  on  the  ends  of  the  branches  are  arranged  much 


FIG.  108.— Leaf  Arrangement  of  Horse-Chestnut 
on  Vertical  Shoots  (side  view). 


142 


FOUNDATIONS   OF  BOTANY 


like  those  of  the  horse-chestnut,  but  they  are  found  to  be 
arranged  more  nearly  flatwise  along  the  inner  portions 
of  the  branches,  that  is,  the  portions  nearer  the  tree. 
Figs.  109  and  110  show  the  remarkable  difference  in 
arrangement  in  different  branches  of  the  Deutzia,  and 
equally  interesting  modifications  may  be  found  in 
alternate-leaved  trees,  such  as  the  elm  and  the  cherry. 


FIG.  109.  — Opposite  Leaves  of  Deutzia1  (from  the  same  shrub  as  Pig.  110),  as 
arranged  on  a  Horizontal  Branch. 

150,  Leaf-Mosaics.  —  In  very  many  cases  the  leaves  at 
the  end  of  a  shoot  are  so  arranged  as  to  form  a  pretty 
symmetrical  pattern,  as  in  the  horse-chestnut  (Fig.  107). 
When  this  is  sufficiently  regular,  usually  with  the  spa'ce 
between  the  leaves  a  good  deal  smaller  than  the  areas  of 
the  leaves  themselves,  it  is  called  a  leaf-mosaic  (Fig.  111). 
Many  of  the  most  interesting  leaf-groups  of  this  sort  (as 

1  Deutzia  crenata. 


LEAF  EXPOSURE  TO  SUN  AND  AIR 


143 


FIG.  110.  —  Opposite  Leaves  of  Deutzia,  as 
arranged  on  a  Vertical  Branch. 


in  the  figure  above  mentioned)  are  found  in  the  so-called 
root-leaves  of  plants.     Good  examples  of  these  are  the 

dandelion,  chicory,  fall 
dandelion,  thistle,  hawk- 
weed,  pyrola,  plantain. 
How  are  the  leaves  of 
these  plants  kept  from 
shading  each  other? 

151.  Much-Divided 
Leaves.  —  Not  infre- 
quently leaves  are  cut 
into  slender  fringe  -  like 
divisions,  as  in  the  carrot, 
tansy,  southernwood, 
wormwood,  yarrow,  dog- 
fennel,  cypress-vine,  and  many  other  common  plants.  This 
kind  of  leaf  seems  to  be  adapted  to  offer  considerable 
surface  to  the  sun  without  cut- 
ting off  too  much  light  from 

other  leaves  underneath.     Such 

• 

a  leaf  is  in  much  less  danger  of 
being  torn  by  severe  winds  than 
are  broader  ones  with  undivided 
margins.  The  same  purposes 
are  served  by  compound  leaves 
with  very  many  small  leaflets, 
such  as  those  of  the  honey- 
locust,  mimosa  acacia  (Fig.  113), 
and  other  trees  and  shrubs  of  the  pea  family.  What  kind 
of  shade  is  produced  by  a  horse-chestnut  or  a  maple  tree 
compared  with  that  of  a  honey-locust  or  an  acacia  ? 


FIG.  111.  —Leaf -Mosaic  of  a  . 
Campanula. 


144  FOUNDATIONS   OF  BOTANY 

152.  Daily  Movements  of  Leaves.  —  Many  compound 
leaves  have  the  power  of  changing  the  position  of  their 
leaflets  to  accommodate  themselves  to  varying  conditions 
of  light  and  temperature.  Some  plants  have  the  power 
of  directing  the  leaves  or  leaflets  edgewise  towards  the 
sun  during  the  hottest  parts  of  the  day,  allowing  them  to 

extend  their  surfaces 
more  nearly  in  a  hori- 
zontal direction  during 
the  cooler  hours. 

The  so-called  "sleep" 
of  plants  has  long  been 
known,  but  this  subject 

FIG.  112.  —  A  Leaf  of  Red  Clover.  J 

At  the  left,  leaf  by  day;  at  the  right,  the  same      has    been  HlOSt   Carefully 

leaf  asleep  at  night.  studied  rather  recently. 

The  wood  sorrel,  or  oxalis,  the  common  bean,  clovers, 
and  the  locust  tree  are  some  of  the  most  familiar  of 
the  plants  whose  leaves  assume  decidedly  different  posi- 
tions at  night  from  those  which  they  occupy  during  the 
day.  Sometimes  the  leaflets  rise  at  night,  and  in  many 
instances  they  droop,  as  in  the  red  clover  (Fig.  112)  and 
the  acacia  (Fig.  113).  One  useful  purpose,  at  any  rate, 
that  is  served  by  the  leafs  taking  the  nocturnal  position  is 
protection  from  frost.  It  has  been  proved  experimentally 
that  when  part  of  the  leaves  on  a  plant  are  prevented  from 
assuming  the  folded  position,  while  others  are  allowed  to 
do  so,  and  the  plant  is  then  exposed  during  a  frosty  night, 
the  folded  ones  may  escape  while  the  others  are  killed. 
Since  many  plants  in  tropical  climates  fold  their  leaves 
at  night,  it  is  certain  that  this  movement  has  other  pur- 
poses than  protection  from  frost,  and  probably  there  is 


LEAF  EXPOSURE  TO  SUN  AND  AIR 


145 


much  yet  to  be  learned  about  the  meaning  and  importance 
of  leaf-movements. 

153.  Cause  of  Sleep-Movements.  —  The  student  may 
very  naturally  inquire  whether  the  change  to  the  noc- 
turnal position  is  brought  about  by  the  change  from  light 
to  darkness  or  whether  it  depends  rather  upon  the  time 
of  day.  It  will  be  interesting  to  try  an  experiment  in 
regard  to  this. 

EXPERIMENT   XXYI 

Remove  a  pot  containing  an  oxalis  from  a  sunny  window  to  a 
dark  closet,  at  about  the  same  temperature,  and  note  at  intervals  of 
five  minutes  the  condition  of  its  leaves  for  half  an  hour  or  more. 


FIG.  113.  — A  Leaf  of  Acacia. 
A,  as  seen  by  day  ;  JB,  the  same  leaf  asleep  at  night. 

154.  Structure  of  the  Parts  which  cause  Leaf -Motions.  — 
In  a  great  number  of  cases  the  daily  movements  of  leaves 
are  produced  by  special  organs  at  the  bases  of  the  leaf- 
stalks. These  cushion-like  organs,  called  pulvini  (Fig. 
114),  are  composed  mainly  of  parenchyinatous  tissue 


146 


FOUNDATIONS   OF  BOTANY 


(Sect.  106),  which  contains  much  water.  It  is  impossible 
fully  to  explain  in  simple  language  the  way  in  which  the 
cells  of  the  pulvini  act,  but  in  a  general  way  it  may  be 
said  that  changes  in  the  light  to  which  the  plant  is  exposed 
cause  rather  prompt  changes  in  the  amount  of  water  in 

the  cells   in   one  portion   or 
other  of  the  pulvinus.    If  the 
cells   on  one   side  are    filled 
fuller   of  water   than  usual, 
that  side  of  the  pulvinus  will 
be  expanded  and  make    the 
leaf-stalk    bend    toward   the 
opposite  side.     The  prompt- 
ness of  these 
movements  is  no 
doubt  in  consid- 
erable   measure 

FIG.  114.  — Compound  Leaf  of  Bean  with  '^'J          due    to    the    fact 

Pulvinus.    (The  pulvinus  shows  as  an  ||  |            .          .          ,               .. 

enlargement,  in  the  figure  about  three-  that  in    the   pul- 

eighths  inch  long,  at  the  base  of  the  yini  /^  in  many 

petiole.)  J 

other    parts    of 

plants)  the  protoplasm  of  adjacent  cells  is  connected. 
Delicate  threads  of  protoplasm  extend  through  the  cell- 
walls,  making  the  whole  tissue  a  living  web,  so  that  any 
suitable  stimulus  or  excitant  which  acts  on  one  part  of 
the  organ  will  soon  affect  the  whole  organ. 

155.  Vertically  Placed  Leaves.  —  Very  many  leaves,  like 
those  of  the  iris  (Fig.  44),  always  keep  their  principal  sur- 
faces nearly  vertical,  thus  receiving  the  morning  and  even- 
ing sun  upon  their  faces,  and  the  noonday  sun  (which  is 
so  intense  as  to  injure  them  when  received  full  on  the 


LEAF  EXPOSURE  TO  SUN  AND  AIR 


147 


surface)  upon  their  edges.  This  adjustment  is  most  per- 
fect in  the  compass-plant  of  the  prairies  of  the  Mississippi 
basin.  Its  leaves  stand  very  nearly  upright,  many  with 


A  B 

FIG.  115.  —Leaves  standing  nearly  Vertical  in  Compass-Plant  (Silphium  laciniatum). 
A,  view  from  east  or  west ;  £,  from  north  or  south. 

their  edges  just  about  north  and  south  (Fig.  115),  so  that 
the  rays  of  the  midsummer  sun  will,  during  every  bright 


148  FOUNDATIONS   OF  BOTANY 

day,  strike  the  leaf-surfaces  nearly  at  right  angles  during 
a  considerable  portion  of  the  forenoon  and  afternoon, 
while  at  midday  only  the  edge  of  each  leaf  is  exposed 
to  the  sun. 

156.  Movements  of  Leaves  and  Stems  toward  or  away 
from  Light  (Heliotropic  Movements).  —  The  student  doubt- 
less  learned  from  his  experiments  with  seedling  plants 
that  their  stems   tend  to  seek  light.      The  whole  plant 
above  ground  usually  bends  toward  the  quarter  from  which 
the  strongest  light  comes.      Such  movements  are  called 
Tieliotropic  from  two  Greek  words  which   mean  turning 
toward  the  sun.     How  do  the  plants  in  a  window  behave 
with  reference  to  the  light  ? 

EXPERIMENT   XXVII 

How  do  Young  Shoots  of  English  Ivy  bend  with  Reference  to  Light  ? 
—  Place  a  thrifty  potted  plant  of  English  ivy  before  a  small  window, 
e.g.,  an  ordinary  cellar  window,  or  in  a  large  covered  box,  painted  dull 
black  within  and  open  only  on  the  side  toward  a  south  window. 
After  some  weeks  note  the  position  of  the  tips  of  the  shoots. 
Explain  the  use  of  their  movements  to  the  plant. 

157.  Positive  and  Negative  Heliotropic  Movements ;  how 
produced.  —  Plants  may  bend  either  toward  or  away  from 
the  strongest  light.     In  the  former  case  they  are  said  to 
show  positive  heliotropism,  in  the  latter  negative  heliotro- 
pism.     In  both  cases  the  movement  is  produced  by  unequal 
growth,  brought  about  by  the  unequal  lighting  of  different 
sides  of  the  stem.     If  the  less  strongly  lighted  side  grows 
faster,  what  kind  of  heliotropism  results?     If  the  more 
strongly  lighted  side  grows  faster,  what  kind  of  heliotro- 
pism results  ?     How  would  a  plant  behave  if  placed  on  a 


LEAF  EXPOSURE  TO  SUN  AND  AIR       149 

revolving  table  before  a  window  and  slowly  turned  during 
the  hours  of  daylight? 

158.    Review  Summary  of  Chapter  X. 

f  For  vertical  twigs 
Leaf  arrangement     .     .     .      <*_      .      .       J  _  ,    . 

L  r  or  horizontal  twigs 

f  Apparatus  for 

Movements  of  leaves  .  .  «  Causes  of 

[  Uses  of 

Compass-plants  .... 

TT  ,.,.,,.  f  Positive 

Heliotropic  bending  of  stems  < 


CHAPTER    XI 

MINUTE   STRUCTURE   OF  LEAVES;    FUNCTIONS  OF 
LEAVES 

159.  Leaf  of  Lily.  —  A  good  kind  of  leaf  with  which 
to  begin  the  study  of  the  microscopical  structure  of  leaves 
in  general  is  that  of  the  lily.1 

160.  Cross-Section  of  Lily  Leaf.  —  The  student  should  first  exam- 
ine with  the  microscope  a  cross-section  of  the  leaf,  that  is,  a  very 
thin  slice,  taken  at  right  angles  to  the  upper  and  under  surfaces  and 
to  the  veins.     This  will  show  : 

(a)  The  upper  epidermis  of  the  leaf,  a  thin,  nearly  transparent 
membrane. 

(6)    The  intermediate  tissues. 

(c)    The  lower  epidermis. 

Use  a  power  of  from  100  to  200  diameters.  In  order  to  ascertain 
the  relations  of  the  parts,  and  to  get  their  names,  consult  Fig.  116. 
Your  section  is  by  no  means  exactly  like  the  figure ;  sketch  it.  Label 
properly  all  the  parts  shown  in  your  sketch. 

Are  any  differences  noticeable  between  the  upper  and  the  lower 
epidermis?  Between  the  layers  of  cells  immediately  adjacent  to 
each? 

161.  Under  Surface  of  Lily  Leaf.  —  Examine  with  a  power  of  200 
or  more  diameters  the  outer  surface  of  a  piece  of  epidermis  from  the 
lower  side  of  the  leaf.2     Sketch  carefully,  comparing  your  sketch 
with  Figs.  117  and  118,  and  labeling  it  to  agree  with  those  figures. 

Examine  another  piece  from  the  upper  surface ;  sketch  it. 
How  does  the  number  of  stomata  in  the  two  cases  compare  ? 

1  Any  kind  of  lily  will  answer. 

2  The  epidermis  may  be  started  with  a  sharp  knife,  then  peeled  off  with 
small  forceps,  and  mounted  in  water  for  microscopical  examination. 

150 


MINUTE   STRUCTURE   OF  LEAVES 


151 


Take  measurements  from  the  last  three  sketches  with  a  scale  and, 
knowing  what  magnifying  power  was  used,  answer  these  questions l  : 
(a)  How  thick  is  the  epidermis  ? 

(&)  What  is  the  length  and  the  breadth  of  the  epidermal  cells  ? 
(c)  What  is  the  average  size  of  the  pulp-cells  ? 

A  stoma  is  a  microscopic  pore  or  slit  in  the  epidermis. 
It  is  bounded  and  opened  and  shut  by  guard-cells  (Fig. 
118,  #),  usually  two  in  number.  These  are  generally 


FIG.  116.  —  Vertical  Section  of  the  Leaf  of  the  Beet.    (Much  magnified.) 

e,  epidermis  ;  p,  palisade-cells'  (and  similar  elongated  cells) ;  r,  cells  filled  with 
red  cell  sap  ;  i,  intercellular  spaces ;  a,  air  spaces  communicating  with  the 
stomata ;  st,  stomata,  or  hreathing  pores. 

1  The  teacher  may  measure  the  size  with  the  camera  lucida. 


152 


FOUNDATIONS   OF  BOTANY 


P-  — 


p  — 


A 


h 


somewhat  kidney-shaped  and  become  more  or  less  curved 
as  they  are  fuller  or  less  full  of  water  (see  Sect.  170). 

162.  Calculation  of  Number  of  Stomata  per  Unit  of  Area. 
—  In  order  to  get  a  fairly  exact  idea  of  the  number  of 
stomata  on  a  unit  of  leaf-surface,  the  most  convenient 

plan  is  to  make 
use  of  a  photo- 
micrograph. The 
bromide  enlarge- 
ment No.  12  of 
the  Tower  series 
represents  about 
a  twenty-five- 
hundredth  of  a 
square  inch  of  the 
lower  epidermis  of 
the  cyclamen  leaf, 
magnified  until  it 
is  about  fifteen 
inches  square. 
Count  the  number 
of  stomata  on  the 
entire  photograph, 
then  calculate  the 
number  of  stomata 
on  a  square  inch 
of  the  surface  of 


st 


FIG.  117.  —Epidermis  of  Leaf  of  Althaea. 

(Much  magnified.) 

A,  from  upper  surface  ;  B,  from  lower  surface. 
h,  star-shaped  compound  hairs  ;  st,  stomata  ;  p, 
upper  ends  of  palisade-cells,  seen  through  the 
epidermis  ;  e,  cells  of  epidermis. 


this  leaf.  If  a  cyclamen  plant  has  twelve  leaves,  each 
with  an  average  area  of  six  square  inches,  calculate  the 
number  of  stomata  of  the  lower  epidermis  of  all  the  leaves 
taken  together. 


MINUTE   STRUCTURE   OF  LEAVES 


153 


cu 


In  the  case  of  an  apple  tree,  where  the  epidermis  of  the 
lower  surface  of  the  leaf  contains  about  24,000  stomata  to 
the  square  inch,  or  the  black  walnut,  with  nearly  300,000 
to  the  square  inch, 
the  total  number 
on  a  tree  is  incon- 
ceivably large. 

163.  Uses  of  the 
Parts  examined.  — 
It  will  be  most  con- 
venient to  discuss 
the  uses  of  the 
parts  of  the  leaf  a 
little  later,  but  it 
will  make  matters 
simpler  to  state  at 
once  that  the  epi- 
dermis serves  as  a 
mechanical  protec- 
tion to  the  parts 
beneath  and  pre- 
vents excessive 
evaporation,  that 
the  palisade-cells 
(which  it  may  not  be  easy  to  make  out  very  clearly  in  a 
roughly  prepared  section)  hold  large  quantities  of  the  green 
coloring  matter  of  the  leaf  in  a  position  where  it  can 
receive  enough  but  not  too  much  sunlight,  and  the  cells 
of  the  spongy  parenchyma  share  the  work  of  the  palisade- 
cells,  besides  evaporating  much  water.  The  stomata 
admit  air  to  the  interior  of  the  leaf  (where  the  air  spaces 


FIG.  118.  —A  Stoma  of  Thyme.    (Greatly  magnified.) 

A,  section  at  right  angles  to  surface  of  leaf ;  S,  sur- 
face view  of  stoma.  cu,  cuticle  ;  g,  guard-cells  ; 
s,  stoma  ;  e,  epidermal  cells ;  a,  air  chamber ; 
c,  cells  of  spongy  parenchyma  with  grains  of 
chlorophyll. 


154 


FOUNDATIONS   OF  BOTANY 


serve  to  store  and  to  distribute  it),  they  allow  oxygen 
and  carbonic  acid  gas  to  escape,  and,  above  all,  they  regu- 
late the  evaporation  of  water  from  the  plant. 

164.  Leaf  of  "India-Rubber  Plant." l  —  Study  with  the  micro- 
scope, as  the  lily  leaf  was  studied,  make  the  same  set  of  sketches, 
note  the  differences  in  structure  between  the  two  leaves,  and  try  to 
discover  their  meaning. 

How  does  the  epidermis  of  the  two  leaves  compare  ? 

Which  has  the  larger  stomata? 

Which  would  better  withstand  great  heat  and  long  drought  ? 

165.  Chlorophyll  as  found  in  the  Leaf.  —  Slice  off  a 
little  of  the  epidermis  from  some  such  soft,  pulpy  leaf  as 


FIG.  119.  — Section  through  Lower  Epidermis  of  Leaf  of  India-Rubber  Plant 

(Ficus  elastica).    (Magnified  330  diameters.) 

o,  opening  of  pit ;  p,  pit  leading  to  stoma ;  s,  stoma,  with  two  guard-cells  ;  w, 
water-storage  cells  of  epidermis  ;  a,  an  air  space ;  around  and  above  the  air 
spaces  are  cells  of  the  spongy  parenchyma. 

that  of  the  common  field  sorrel,2  live-for-ever,  or  spinach ; 
scrape  from  the  exposed  portion  a  very  little  of  the  green 
pulp  ;  examine  with  the  highest  power  attainable  with 
your  microscope,  and  sketch  several  cells. 

1  Ficus  elastica,  a  kind  of  fig  tree. 

2  Rumex  Acetosella. 


MINUTE   STRUCTURE   OF  LEAVES 


155 


Notice  that  the  green  coloring  matter  is  not  uniformly 
distributed,  but  that  it  is  collected  into  little  particles 
called  chlorophyll  bodies  (Fig.  120,  p). 

166.  Woody  Tissue  in  Leaves.  —  The  veins  of  leaves 
consist  of  fibre-vascular  bundles  containing  wood  and 
vessels  much  like  those  of  the  stem 
of  the  plant.  Indeed,  these  bundles 
in  the  leaf  are  continuous  with  those 
of  the  stem,  and  consist  merely  of 
portions  of  the  latter,  looking 
as  if  unraveled,  which  pass  ; 
outward  and  upward  from  the 
stem  into  the  leaf  under 
the  name  of  leaf-traces. 
These  traverse  the  peti- 
ole often  in  a  somewhat 
irregular  fashion. 


EXPERIMENT   XXVIII 
of    Water     from 


FIG.  120.  —  Termination 
of  a  Vein  in  a  Leaf. 
(Magnified  about  345 
diameters.) 

v,  spirally  thickened  cells 

Stem    to    Leaf. —Place    a      Of  the  vein  5jp,  paren- 

freshly  cut  leafy  shoot  of  some     chyma-cells  of  the 

.  spongy  interior  of  the 

plant  with  large  thin  leaves,     ieaf,  with  chlorophyll 

such  as  Hydrangea  hortensia,     1°*™*'  n>  nucleated 

in  eosin   solution   for  a  few 

minutes.     As  soon  as  the   leaves  show  a   decided  reddening,  pull 

some  of  them  off  and  sketch  the  red  stains  on  the  scars  thus  made. 

What  does  this  show? 

167.    Experimental  Study  of  Functions  of  Leaves.  —  The 

most  interesting  and  profitable  way  in  which  to  find  out 
what  work  leaves  do  for  the  plant  is  by  experimenting 
upon  them.  Much  ,that  relates  to  the  uses  of  leaves  is 


156  FOUNDATIONS   OF  BOTANY 

not  readily  shown  in  ordinary  class-room  experiments,  but 
some  things  can  readily  be  demonstrated  in  the  experi- 
ments which  follow. 

EXPERIMENT   XXIX 

Transpiration.  — Take  two  twigs  or  leafy  shoots  of  any  thin-leafed 
plant ; l  cover  the  cut  end  of  each  stem  with  a  bit  of  grafting  wax  2 
to  prevent  evaporation  from  the  cut  surface.  Put  one  shoot  into  a 
fruit  jar,  screw  the  top  on,  and  leave  in  a  warm  room;  put  the  other 
beside  it,  and  allow  both  to  remain  some  hours.  Examine  the 
relative  appearance  of  the  two,  as  regards  wilting,  at  the  end  of  the 
time. 

Which  shoot  has  lost  most  ?  Why  ?  Has  the  one  in  the  fruit 
jar  lost  any  water  ?  To  answer  this  question,  put  the  jar  (without 
opening  it)  into  a  refrigerator ;  or,  if  the  weather  is  cold,  put  it  out 
of  doors  for  a  few  minutes,  and  examine  the  appearance  of  the  inside 
of  the  jar.  What  does  this  show  ?  3 

168.  Uses  of  the  Epidermis.4  —  The  epidermis,  by  its 
toughness,  tends  to  prevent  mechanical  injuries  to  the 
leaf,  and  after  the  filling  up  of  a  part  of  its  outer  por- 
tion with  a  corky  substance  it  greatly  diminishes  the  loss  of 
water  from  the  general  surface.  This  process  of  becom- 
ing filled  with  cork  (or  a  substance  of  similar  properties 
known  as  cutiri)  is  absolutely  essential  to  the  safety  of 
leaves  or  young  portions  of  stems  which  have  to  with- 
stand heat  and  dryness.  The  corky  or  cutinized  cell- 
wall  is  waterproof,  while  ordinary  cellulose  allows  water 

1  Hydrangea,  squash,  melon,  or  cucumber  is  best;  many  other  kinds  will 
answer  very  well. 

2  Grafting  wax  may  be  bought  of  nurserymen  or  seedsmen. 

3  If  the  student  is  in  doubt  whether  the  jar  filled  with  ordinary  air  might 
not  behave  in  the  same  way,  the  question  may  be  readily  answered  by  putting 
a  sealed  jar  of  air  into  the  refrigerator. 

*  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  pp.  273-362. 


MINUTE   STRUCTURE   OF  LEAVES 


157 


to  soak  through  it  with  ease.  Merely  examining  sections 
of  the  various  kinds  of  epidermis  will  not  give  nearly 
as  good  an  idea  of  their  properties  as  can  be  obtained 
by  studying  the  behavior  during  severe  droughts  of 
plants  which  have  strongly  cutinized  surfaces  and  of 
those  which  have  not.  Fig.  121,  however,  may  convey 
some  notion  of  the  difference  between  the  two  kinds  of 
structure.  In  most 
cases,  as  in  the  india- 
rubber  tree,  the  ex- 
ternal epidermal  cells 
(and  often  two  or 
three  layers  of  cells 
beneath  these)  are 
filled  with  water,  and 
thus  serve  as  reser- 
voirs from  which  the 
outer  parts  of  the  leaf 
and  the  stem  are  at 
times  supplied. 

In  many  cases,  noticeably  in  the  cabbage,  the  epidermis 
is  covered  with  a  waxy  coating,  which  doubtless  increases 
the  power  of'  the  leaf  to  retain  needed  moisture,  and 
which  certainly  prevents  rain  or  dew  from  covering  the 
leaf-surfaces,  especially  the  lower  surfaces,  so  as  to  hinder 
the  operation  of  the  stomata.  Many  common  plants,  like 
the  meadow  rue  and  the  nasturtium,  possess  this  power 
to  shed  water  to  such  a  degree  that  the  under  surface  of 
the  leaf  is  hardly  wet  at  all  when  immersed  in  water. 
The  air-bubbles  on  such  leaves  give  them  a  silvery 
appearance  when  held  under  water. 


FIG.  121.  —  Unequal  Development  of  Cuticle 

by  Epidermis-Cells. 

A,  epidermis  of  Butcher's  Broom  (Ruscus) ;  B, 
epidermis  of  sunflower ;  c,  cuticle ;  e,  epi- 
dermis-cells. 


158  FOUNDATIONS   OF  BOTANY 

169.  Hairs  on  Leaves.  —  Many  kinds  of  leaves  are  more 
or   less   hairy  or  downy,   as    those   of   the    mullein,   the 
"mullein   pink,"   many   cinquefoils,   and   other   common 
plants.     In  some  instances  this  hairiness  may  be  a  protec- 
tion against  snails  or  other  small  leaf-eating  animals,  but 
in  other  cases  it  seems  to  be  pretty  clear  that  the  woolli- 
ness  (so  often  confined  to  the  under  surface)  is  to  lessen 
the  loss   of  water  through  the  stomata.     The  Labrador 
tea  is  an  excellent  example  of  a  plant,  with  a  densely 
woolly  coating  on  the  lower  surface  of  the  leaf.     The 
leaves,  too,  are  partly  rolled  up  (see  Fig.  224),  with  the 
upper  surface  outward,  so  as  to  give  the  lower  surface 
a  sort  of  deeply  grooved  form,  and  on  the  lower  surface 
all  of   the  stomata   are   placed.     This  plant,  like  some 
others  with  the  same  characteristics,  ranges  far  north  into 
regions    where    the    temperature,    even    during    summer, 
often  falls  so  low  that  absorption  of  water  by  the  roots 
ceases,  since  it  has  been  shown  that  this  nearly  stops  a 
little  above  the  freezing  point  of  water  (see  Exp.  XVII). 
Exposed  to  cold,  dry  winds,  the  plant  would  then  often 
be  killed  by  complete  drying  if  it  were  not  for  the  pro- 
tection afforded  by  the  woolly,  channeled  under  surfaces 
of  the  leaves.1 

170.  Operation  of  the  Stomata.  —  The  stomata  serve  to 
admit  air  to  the  interior  of  the  leaf,  and  to  allow  moisture, 
in  the  form  of  vapor,  to  pass  out  of  it.     They  do  this  not 
in  a  passive  way,  as  so  many  mere  holes  in  the  epidermis 
might,   but  to  a  considerable   extent  they   regulate  the 
rapidity  of  transpiration,  opening  more  widely  in  damp 
weather  and  closing   in    dry    weather.     The    opening  is 

1  This  adaptation  is  sufficiently  interesting  for  class  study. 


PLATE  IV.  —  A  Cypress  Swamp 


MINUTE   STRUCTURE   OF  LEAVES  159 

caused  by  each  of  the  guard-cells  bending  into  a  more 
kidnejr-like  form  than  usual,  and  the  closing  by  a  straight- 
ening out  of  the  guard-cells.  The  under  side  of  the  leaf, 
free  from  palisade-cells,  abounding  in  intercellular  spaces, 
and  pretty  well  protected  from  becoming  covered  with 
rain  or  dew,  is  especially  adapted  for  the  working  of  the 
stomata,  and  accordingly  we  usually  find  them  in  much 
greater  numbers  on  the  lower  surface.  On  the  other 
hand,  the  little  flowerless  plants  known  as  liverworts, 
which  lie  prostrate  on  the  ground,  have  their  stomata  on 
the  upper  surface,  and  so  do  the  leaves  of  pond  lilies, 
which  lie  flat  on  the  water.  In  those  leaves  which  stand 
with  their  edges  nearly  vertical,  the  stomata  are  dis- 
tributed somewhat  equally  on  both  surfaces.  Stomata 
occur  in  the  epidermis  of  young  stems,  being  replaced 
later  by  the  lenticels.  Those  plants  which,  like  the  ( 
cacti,  have  no  ordinary  leaves,  transpire  through  the 
stomata  scattered  over  their  general  surfaces. 

The  health  of  the  plant  depends  largely  on  the  proper 
working  condition  of  the  stomata,  and  one  reason  why 
plants  in  cities  often  fail  to  thrive  is  that  the  stomata 
become  choked  with  dust  and  soot.  In  some  plants,  as 
the  oleander,  provision  is  made  for  the  exclusion  of  dust 
by  a  fringe  of  hairs  about  the  opening  of  each  stoma.  If 
the  stomata  were  to  become  filled  with  water,  their  activ- 
ity would  cease  until  they  were  freed  from  it;  hence 
many  plants  have  their  leaves,  especially  the  under  sur- 
faces, protected  by  a  coating  of  wax  which  sheds  water. 

171.  Measurement  of  Transpiration.  —  We  have  already 
proved  that  water  is  lost  by  the  leaves,  but  it  is  worth 
while  to  perform  a  careful  experiment  to  reduce  our 


160 


FOUNDATIONS  OF  BOTANY 


knowledge  to  an  exact  form,  to  learn  how  much  water 
a  given  plant  transpires  under  certain  conditions.  It  is 
also  desirable  to  find  out  whether  different  kinds  of  plants 
transpire  alike,  and  what  changes  in  the  temperature,  the 
dampness  of  the  air,  the  brightness  of  the  light,  to  which 
a  plant  is  exposed,  have  to  do  with  its  transpiration. 
Another  experiment  will  show  whether  both  sides  of  a 
leaf  transpire  alike. 

EXPERIMENT   XXX 

Amount  of  Water  lost  by  Transpiration.  —  Procure  a  thrifty  hydran- 
gea1 and  a  small  "india-rubber  plant,"2  each  growing  in  a  small 

flower-pot,  and  with  the  number 
of  square  inches  of  leaf-surface 
in  the  two  plants  not  too  widely 
different.  Calculate  the  area  of 
the  leaf-surface  for  each  plant, 
by  dividing  the  surface  of  a  piece 
of  tracing  cloth  into  a  series  of 
squares  one-half  inch  on  a  side, 
holding  an  average  leaf  of  each 
plant  against  this  and  counting 
the  number  of  squares  and  parts 
of  squares  covered  by  the  leaf. 
Or  weigh  a  square  inch  of  tinfoil 
on  a  very  delicate  balance,  cut 
out  a  piece  of  the  same  kind  of 
tinfoil  of  the  size  of  an  average 
leaf,  weigh  this  and  calculate  the 
leaf -area  from  the  two  weights. 
This  area,  multiplied  by  the  number  of  leaves  for  each  plant,  will 
give  approximately  the  total  evaporating  surface  for  each. 

Transfer  each  plant  to  a  glass  battery  jar  of  suitable  size.     Cover 


FIG.  122.  —  A  Hydrangea  potted  in  a 
Battery  Jar  for  Exp.  XXX. 


1  The  common  species  of  the  greenhouses,  Hydrangea  hortensia. 

2  This  is  really  a  fig,  Ficus  elastica. 


MINUTE   STRUCTURE   OF  LEAVES  161 

the  jar  with  a  piece  of  sheet  lead,  slit  to  admit  the  stem  of  the  plant, 
invert  the  jar  and  seal  the  lead  to  the  glass  with  a  hot  mixture  of 
beeswax  and  rosin.  Seal  up  the  slit  and  the  opening  about  the 
stem  with  grafting  wax.  A  thistle-tube,  such  as  is  used  by  chem- 
ists, is  also  to  be  inserted,  as  shown  in  Fig.  122.1  The  mouth  of  this 
may  be  kept  corked  when  the  tube  is  not  in  use  for  watering. 

Water  each  plant  moderately  and  weigh  the  plants  separately  on 
a  balance  that  is  sensitive  to  one  or  two  grams.  Record  the  weights, 
allow  the  plants  to  stand  in  a  sunny,  warm  room  for  twenty-four 
hours  and  reweigh. 

Add  to  each  plant  just  the  amount  of  water  which  is  lost,2  and 
continue  the  experiment  in  the  same  manner  for  several  days  so  as 
to  ascertain,  if  possible,  the  effect  upon  transpiration  of  varyi rig- 
amounts  of  water  in  the  atmosphere. 

Calculate  the  average  loss  per  100  square  inches  of  leaf-surface  for 
each  plant  throughout  the  whole  course  of  the  experiment.  Divide 
the  greater  loss  by  the  lesser  to  find  their  ratio.  Find  the  ratio  of 
each  plant's  greatest  loss  per  day  to  its  least  loss  per  day,  and  by 
comparing  these  ratios  decide  which  transpires  more  regularly. 

Try  the  effect  of  supplying  very  little  water  to  each,  so  that  the 
hydrangea  will  begin  to  droop,  and  see  whether  this  changes  the 
relative  amount  of  transpiration  for  the  two  plants.  Vary  the  con- 
ditions of  the  experiment  for  a  day  or  two  as  regards  temperature, 
and  again  for  a  day  or  two  as  regards  light,  and  note  the  effect  upon 
the  amount  of  transpiration. 

The  structure  of  the  fig  (India-rubber  plant)  leaf  has  already  been 
studied.  That  of  the  hydrangea  is  looser  in  texture  and  more  like 
the  leaf  of  the  lily  or  the  beet  (Fig.  116). 

What  light  does  the  structure  throw  on  the  results  of  the  pre- 
ceding experiment  ? 

1  It  will  be  much  more  convenient  to  tie  the  hydrangea  if  one  has  been 
chosen  that  has  but  a  single  main  stem.    Instead  of  the  hydrangea,  the  com- 
mon cineraria,  Senecio  cruentus,  does  very  well. 

2  The  addition  of  known  amounts  of  water  may  be  made  most  conveniently 
by  measuring  it  in  a  cylindrical  graduate. 


162  FOUNDATIONS   OF   BOTANY 


EXPERIMENT   XXXI 

Through  which  Side  of  a  Leaf  of  the  India-Rubber  Plant  does  Tran- 
spiration occur?  —  The  student  may  already  have  found  (Sect.  164) 
that  there  are  no  stomata  on  the  upper  surface  of  the  fig  leaf  which 
he  studied.  That  fact  makes  this  leaf  an  excellent  one  by  means  of 
which  to  study  the  relation  of  stomata  to  transpiration. 

Take  two  large,  sound  rubber-plant  leaves,  cut  off  pretty  close  to 
the  stem  of  the  plant.  Slip  over  the  cut  end  of  the  petiole  of  each 
leaf  a  piece  of  small  rubber  tubing,  wire  this  on,  leaving  about  half 
of  it  free,  then  double  the  free  end  over  and  wire  tightly,  so  as  to 
make  the  covering  moisture-proof.  Warm  some  vaseline  or  grafting 
wax  until  it  is  almost  liquid,  and  spread  a  thin  layer  of  it  smoothly 
over  the  upper  surface  of  one  leaf  and  the  lower  surface  of  the  other. 
Hang  both  up  in  a  sunny  place  in  the  laboratory  and  watch  them  for 
a  month  or  more. 

What  difference  in  the  appearance  of  the  two  leaves  becomes 
evident  ?  What  does  the  experiment  prove  ? 

172.  Endurance  of  Drought  by  Plants.  — Plants  in  a  wild 
state  have  to  live  under  extremely  different  conditions  as 
regards  water  supply  (see  Chapter  XXIV).  Observation 
of  growing  plants  during  a  long  drought  will  quickly 
show  how  differently  the  various  species  of  a  region  bear 
the  hardships  due  to  a  scanty  supply  of  moisture.  It  is 
still  easier,  however,  to  subject  some  plants  to  an  artificial 
drought  and  watch  their  condition. 

EXPERIMENT  XXXII 

Resistance  to  Drought.  —  Procure  at  least  one  plant  from  each  of 
these  groups  : 

Group  I.  Melon-cactus  (Echinocactus  or  Mamillaria),  prickly 
pear  cactus. 

Group  II.    Aloe,  Cotyledon  (often  called  Echeveria),  houseleek. 


MINUTE  STRUCTURE  OF  LEAVES        163 

Group  III.  Live-for-ever  (Sedum  Telephium),  Bryophyllum,  English 
ivy,  "  ivy-leafed  geranium,"  (Pelargonium  peltatum),  or  any  of  the 
fleshy-leafed  begonias. 

Group  IV.  Hydrangea  (H.  hortensia),  squash  or  cucumber,  sun- 
flower. 

The  plants  should  be  growing  in  pots  and  well  rooted.  Water 
them  well  and  then  put  them  all  in  a  warm,  sunny  place.  Note  the 
appearance  of  all  the  plants  at  the  end  of  twenty-four  hours.  If  any 
are  wilting  badly,  water  them.  Keep  on  with  the  experiment,  in  no 
case  watering  any  plant  or  set  of  plants  until  it  has  wilted  a  good 
deal.  Record  the  observations  in  such  a  way  as  to  show  just  how 
long  a  time  it  took  each  plant  to  begin  to  wilt  from  the  time  when 
the  experiment  began.  If  any  hold  out  more  than  a  month,  they 
may  afterwards  be  examined  at  intervals  of  a  week,  to  save  the  time 
required  for  daily  observations.  If  possible,  account  by  the  struc- 
ture of  the  plants  for  some  of  the  differences  observed.  Try  to  learn 
the  native  country  of  each  plant  used  and  the  soil  or  exposure  natural 
to  it. 

173,  Course  traversed  by  Water  through  the  Leaf.  —  The 
same  plan  that  was  adopted  to  trace  the  course  of  water  in 
the  stem  (Exp.  XXI)  may  be  followed  to  discover  its  path 
through  the  leaf. 

EXPERIMENT  XXXIII 

Rise  of  Sap  in  Leaves.  —  Put  the  freshly  cut  ends  of  the  petioles 
of  several  thin  leaves  of  different  kinds  into  small  glasses,  each  con- 
taining eosin  solution  to  the  depth  of  one-quarter  inch  or  more. 
Allow  them  to  stand  for  half  an  hour,  and  examine  them  by  holding 
up  to  the  light  and  looking  through  them  to  see  into  what  parts  the 
eosin  solution  has  risen.  Allow  some  of  the  leaves  to  remain  as 
much  as  twelve  hours,  and  examine  them  again.  The  red-stained 
portions  of  the  leaf  mark  the  lines  along  which,  under  natural  con- 
ditions, sap  rises  into  it.  Cut  across  (near  the  petiole  or  midrib 
ends)  all  the  principal  veins  of  some  kind  of  large,  thin  leaf.  Then 
cut  off  the  petiole  and  at  once  stand  the  cut  end,  to  which  the  blade 


164  FOUNDATIONS   OF  BOTANY 

is  attached,  in  eosin  solution.     Repeat  with  another  leaf  and  stand 
in  water.     What  do  the  results  teach  ? 

174.  Total  Amount  of  Transpiration.  —  In  order  to  pre- 
vent wilting,  the  rise  of  sap  during  the  life  of  the  leaf 
must  have  kept  pace  with  the  evaporation  from  its  sur- 
face. The  total  amount  of  water  that  travels  through  the 
roots,  stems,  and  leaves  of  most  seed-plants  during  their 
lifetime  is  large,  relative  to  the  weight  of  the  plant  itself. 
During  173  days  of  growth  a  corn-plant  has  been  found  to 
give  off  nearly  31  pounds  of  water.  During  140  days  of 
growth  a  sunflower-plant  gave  off  about  145  pounds.  A 
grass-plant  has  been  found  to  give  off  its  own  weight  of 
water  every  twenty-four  hours  in  hot,  dry  summer  weather. 
This  would  make  about  6  ^  tons  per  acre  every  twenty-four 
hours  for  an  ordinary  grass-field,  or  rather  over  2200  pounds 
of  water  from  a  field  50  X  150  feet,  that  is,  not  larger  than 
a  good-sized  city  lot.  Calculations  based  on  observations 
made  by  the  Austrian  forest  experiment  stations  showed 
that  a  birch  tree  with  200,000  leaves,  standing  in  open 
ground,  transpired  on  hot  summer  days  from  700  to  900 
pounds,  while  at  other  times  the  amount  of  transpiration 
was  probably  not  more  than  18  to  20  pounds.1 

These  large  amounts  of  water  are  absorbed,  carried 
through  the  tissues  of  the  plant,  and  then  given  off  by  the 
leaves  simply  because  the  plant-food  contained  in  the  soil- 
water  is  in  a  condition  so  diluted  that  great  quantities  of 
water  must  be  taken  in  order  to  secure  enough  of  the  min- 
eral and  other  substances  which  the  plant  demands  from 
the  soil. 

1  See  B.  E.  Fernow's  discussion  in  Report  of  Division  of  Forestry  of  U.  S. 
Department  of  Agriculture,  1889. 


MINUTE  STRUCTURE  OF  LEAVES        165 

Meadow  hay  contains  about  two  per  cent  of  potash,  or 
2000  parts  in  100,000,  while  the  soil- water  of  a  good  soil 
does  not  contain  more  than  one-half  part  in  100,000  parts. 
It  would  therefore  take  4000  tons  of  such  water  to  furnish 
the  potash  for  one  ton  of  hay.  The  water  which  the 
root-hairs  take  up  must,  however,  contain  far  more  potash 
than  is  assumed  in  the  calculation  above  given,  so  that  the 
amount  of  water  actually  used  in  the  growth  of  a  ton  of 
hay  cannot  be  much  more  than  260  tons.1 

175.  Accumulation  of  Mineral  Matter  in  the  Leaf.  —  Just 
as  a  deposit  of  salt  is  found  in  the  bottom  of  a  seaside  pool 
of  salt  water  which  has  been  dried  up  by  the  sun,  so  old 
leaves  are  found  to  be  loaded  with  mineral  matter,  left 
behind  as  the  sap  drawn  up  from  the  roots  is  evaporated 
through  the  stomata.     A  bonfire  of  leaves  makes  a  sur- 
prisingly large  heap  of  ashes.     An  abundant  constituent 
of  the  ashes  of  burnt  leaves  is  silica,  a  substance  chemic- 
ally the  same  as  sand.     This  the  plant  is  forced  to  absorb 
along  with  the  potash,  compounds  of  phosphorus,  and  other 
useful  substances  contained  in  the  soil-water;  but  since 
the  silica  is  of  hardly  any  value  to  most  plants,  it  often 
accumulates  in  the  leaf  as  so  much  refuse.     Lime  is  much 
more  useful  to  the  plant  than  silica,  but  a  far  larger  quan- 
tity of  it  is  absorbed  than  is  needed;  hence  it,  too,  accu- 
mulates in  the  leaf. 

176.  Nutrition,  Metabolism.2  —  The  manufacture  of  the 
more  complex  plant-foods,  starch,  sugar,  and  so  on,  from 

1  See  the  article,  "  Water  as  a  Factor  in  the  Growth  of  Plants,"  by  B.  T. 
Galloway  and  Albert  F.  Woods,  Year-Book  of  U.  S.  Department  of  Agriculture, 
1894. 

2  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  pp.  371-483. 
Also  Pfeffer's  Physiology  of  Plants,  translated  by  Ewart,  Chapter  VIII. 


166  FOUNDATIONS   OF  BOTANY 

the  raw  materials  which  are  afforded  by  the  earth  and  air 
and  all  the  steps  of  the  processes  by  which  these  foods  are 
used  in  the  life  and  growth  of  the  plant  are  together  known 
as  its  nutrition.  When  we  think  more  of  the  chemical 
side  of  nutrition  than  of  its  relation  to  plant-life,  we  call 
any  of  the  changes  or  all  of  them  metabolism,  which  means 
simply  chemical  transformation  in  living  tissues.  There 
are  two  main  classes  of  metabolism  —  the  constructive  kind, 
which  embraces  those  changes  which  build  up  more  com- 
plicated substances  out  of  simpler  ones  (Sect.  179),  and  the 
destructive  kind,  the  reverse  of  the  former  (Sect.  184).  A 
good  many  references  to  cases  of  plant  metabolism  have 
been  made  in  earlier  chapters,  but  the  subject  comes  up  in 
more  detail  in  connection  with  the  study  of  the  work  of  leaves 
than  anywhere  else,  because  the  feeding  which  the  ordinary 
seed-plant  does  is  very  largely  done  in  and  by  its  leaves. 

177.  Details  of  the  Work  of  the  Leaf.  —  A  leaf  has  four 
functions  to  perform :    (1)    Starch-making ;    (2)    assimila- 
tion ; *  (3)  excretion  of  water  ;  (4)  respiration. 

178.  Absorption  of  Carbon  Dioxide   and  Removal  of  its 
Carbon.  —  Carbon  dioxide  is  a  constant  ingredient  of  the 
atmosphere,  usually  occurring  in  the  proportion  of  about 
four  parts  in  every  10,000  of  air  or  one  twenty-fifth  of  one 
per  cent.     It  is  a  colorless  gas,  a  compound  of  two  simple 
substances  or  elements,  carbon  and  oxygen,    the  former 
familiar  to  us  in  the  forms  of  charcoal  and  graphite,  the 
latter  occurring  as  the  active  constituent  of  air. 

1  In  many  works  on  Botany  (1)  and  (2)  are  both  compounded  under  the 
term  assimilation.  Many  botanists  (most  of  the  American  ones)  apply  the 
name  photosynthesis  or  photosyntax  to  the  starch-making  process,  but  these 
names  are  not  wholly  satisfactory,  and  perhaps  it  is  as  well  (as  suggested  by 
Professor  Atkinson)  to  name  the  process  from  its  result. 


MINUTE  STRUCTURE  OF  LEAVES        167 

Carbon  dioxide  is  produced  in  immense  quantities  by 
the  decay  of  vegetable  and  animal  matter,  by  the  respira- 
tion of  animals,  and  by  all  fires  in  which  wood,  coal,  gas, 
or  petroleum  is  burned. 

Green  leaves  and  the  green  parts  of  plants,  when  they 
contain  a  suitable  amount  of  potassium  salts,  have  the 
power  of  removing  carbon  dioxide  from  the  air  (or  in 
the  case  of  some  aquatic  plants  from  water  in  which  it  is 
dissolved),  retaining  its  carbon  and  setting  free  part  or  all 
of  the  oxygen.  This  process  is  an  important  part  of  the 
work  done  by  the  plant  in  making  over  raw  materials  into 
food  from  which  it  forms  its  own  substance. 

EXPERIMENT   XXXIV 

Oxygen-Making  in  Sunlight.  —  Place  a  green  aquatic  plant  in  a 
glass  jar  full  of  ice-cold  fresh  water,  in  front  of  a  sunny  window.1 
Place  a  thermometer  in  the  jar,  watch  the  rise  of  temperature,  and 
note  at  what  point  you  first  observe  the  formation  of  oxygen  bub- 
bles. Remove  to  a  dark  closet  for  a  few  minutes  and  examine  by 
lamplight,  to  see  whether  the  rise  of  bubbles  still  continues. 

This  gas  may  be  shown  to  be  oxygen  by  collecting  some 
of  it  in  a  small  inverted  test-tube  filled  with  water  and 
thrusting  the  glowing  coal  of  a  match  just  blown  out  into 
the  gas.  It  is  not,  however,  very  easy  to  do  this  satisfac- 
torily before  the  class. 

Repeat  the  experiment,  using  water  which  has  been  well  boiled 
and  then  quickly  cooled.  Boiling  removes  all  the  dissolved  gases 
from  water,  and  they  are  not  re-dissolved  in  any  considerable  quantity 
for  many  hours. 

1  Elodea,  Myriophyllum,  Chrysosplenium,  Potamogeton,  Fontinalis,  any  of 
the  green  aquatic  flowering  plants,  or  even  the  common  confervaceous  plants, 
known  as  pond-scum  or  "  frog-spit,"  will  do  for  this  experiment. 


168  FOUNDATIONS   OF   BOTANY 

Ordinary  air,  containing  a  known  per  cent  of  carbon  dioxide, 
if  passed  very  slowly  over  the  foliage  of  a  plant  covered  with  a  bell- 
glass  and  placed  in  full  sunlight,  will,  if  tested  chemically,  on  com- 
ing out  of  the  bell-glass  be  found  to  have  lost  a  little  of  its  carbon 
dioxide.  The  pot  in  which  the  plant  grows  must  be  covered  with  a 
lid,  closely  sealed  on,  to  prevent  air  charged  with  carbon  dioxide  (as 
the  air  of  the  soil  is  apt  to  be)  from  rising  into  the  bell-glass. 

179.  Disposition  made  of  the  Absorbed  Carbon  Dioxide. 
—  It  would  lead  the  student  too  far  into  the  chemistry  of 
botany  to  ask  him  to  follow  out  in  detail  the  changes  by 
which  carbon  dioxide  lets  go  part  at  least  of  its  oxygen 
and  gives  its  remaining  portions,  namely,  the  carbon,  and 
perhaps  part  of  its  oxygen,  to  build  up  the  substance  of 
the  plant.  Starch  is  composed  of  three  elements  :  hydro- 
gen (a  colorless,  inflammable  gas,  the  lightest  of  known 
substances),  carbon,  and  oxygen.  Water  is  composed 
largely  of  hydrogen,  and,  therefore,  carbon  dioxide  and 
water  contain  all  the  elements  necessary  for  making  starch. 
The  chemist  cannot  put  these  elements  together  to  form 
starch,  but  the  plant  can  do  it,  and  at  suitable  temperatures 
starch-making  goes  on  constantly  in  the  green  parts  of 
plants  when  exposed  to  sunlight  and  supplied  with  water 
and  carbon  dioxide.1  The  seat  of  the  manufacture  is  in 
the  chlorophyll  bodies,  and  protoplasm  is  without  doubt  the 
manufacturer,  but  the  process  is  not  understood  by  chemists 
or  botanists.  No  carbon  dioxide  can  be  taken  up  and  used 
by  plants  growing  in  the  dark,  nor  in  an  atmosphere  con- 
taining only  carbon  dioxide,  even  in  the  light. 

1  Very  likely  the  plant  makes  sugar  first  of  all  and  then  rapidly  changes 
this  into  starch.  However  that  may  be,  the  first  kind  of  food  made  in  the 
leaf  and  retained  long  enough  to  be  found  there  by  ordinary  tests  is  starch. 
See  Pfeffer's  Phi/siology  of  Plants,  translated  by  Ewart,  Vol.  I,  pp.  317,  318. 


PLATE  V.  —  A  Saprophyte,  Indian  Pipe 


MINUTE    STRUCTURE   OF   LEAVES  169 

A  very  good  comparison  of  the  leaf  to  a  mill  has  been 
made  as  follows  l : 

The  mill :  Palisade-cells  and  underlying 

cells  of  the  leaf. 

Raw  material  used  :  Carbon  dioxide,  water. 

Milling  apparatus  :  Chlorophyll  grains. 
Energy  by  which  the  mill 

is  run :  Sunlight. 

Manufactured  product :  Starch. 

Waste  product :  Oxygen. 

180.  Plants  Destitute  of  Chlorophyll  not  Starch-Makers. 

—  Aside  from  the  fact  that  newly  formed  starch  grains  are 
first  found  in  the  chlorophyll  bodies  of  the  leaf  and  the 
green  layer  of  the  bark,  one  of  the  best  evidences  of 
the  intimate  relation  of  chlorophyll  to  starch-making  is 
derived  from  the  fact  that  plants  which  contain  no  chloro- 
phyll cannot  make  starch  from  water  and  carbon  dioxide. 
Parasites,  like  the  dodder,  which  are  nearly  destitute  of 
green  coloring  matter,  cannot  do  this;  neither  can  sapro- 
phytes or  plants  which  live  on  decaying  or  fermenting 
organic  matter,  animal  or  vegetable.  Most  saprophytes, 
like  the  moulds,  toadstools,  and  yeast,  are  flowerless  plants 
of  low  organization,  but  there  are  a  few  (such  as  the 
Indian  pipe  (Plate  V),  which  flourishes  on  rotten  wood 
or  among  decaying  leaves)  that  bear  flowers  and  seeds. 

181.  Detection  of   Starch  in  Leaves.  —  Starch   may  be 
found  in  abundance  by  microscopical  examination  of  the 
green  parts  of  growing  leaves,   or  its  presence  may  be 
shown  by  testing  the  whole  leaf  with  iodine  solution. 

1  By  Professor  George  I,.  Goodale. 


170 


FOUNDATIONS   OF   BOTANY 


EXPERIMENT   XXXV 

Occurrence  of  Starch  in  Nasturtium  Leaves.  —  Toward  the  close  of 
a  veiy  sunny  day  collect  some  bean  leaves  or  leaves  of  nasturtium 
(Tropwolum).  Boil  these  in  water  for  a  few  minutes,  to  kill  the 
protoplasmic  contents  of  the  cells  and  to  soften  and  swell  the  starch 
grains.1 

Soak  the  leaves,  after  boiling,  in  strong  alcohol  for  a  day  or  two, 
to  dissolve  out  the  chlorophyll,  which  would  otherwise  make  it  diffi- 
cult to  see  the  blue  color  of  the  starch  test,  if  any  were  obtained. 
Rinse  out  the  alcohol  with  plenty  of  water 
and  then  place  the  leaves  for  ten  or  fifteen 
minutes  in  a  solution  of  iodine,  rinse  off 
with  water  and  note  what  portions  of  the 
leaf,  if  any,  show  the  presence  of  starch. 

EXPERIMENT   XXXYI 

Consumption  of  Starch  in  Nasturtium 
(Tropceolum)  Leaves. — Select  some  healthy 
leaves  of  Tropaeolum  on  a  plant  growing 
vigorously  indoors  or,  still  better,  in  the 
open  air.  Shut  off  the  sunlight  from 
parts  of  the  selected  leaves  (which  are  to 
be  left  on  the  plant  and  as  little  injured 
as  may  be)  by  pinning  circular  disks  of  cork  on  opposite  sides  of 
the  leaf,  as  shown  in  Fig.  123.  On  the  afternoon  of  the  next  day 
remove  these  leaves  from  the  plant  and  treat  as  described  in  the 
preceding  experiment,  taking  especial  pains  to  get  rid  of  all  the 
chlorophyll  by  changing  the  alcohol  as  many  times  as  may  be  neces- 
sary. What  does  this  experiment  show  in  regard  to  the  consump- 
tion of  starch  in  the  leaf?  What  has  caused  its  disappearance? 

182.  Rate  at  which  Starch  is  manufactured.  —  The 
amount  of  starch  made  in  a  day  by  any  given  area  of 

1  The  leaves,  collected  as  above  described,  may,  after  boiling,  be  kept  in 
alcohol  for  winter  use.  They  also  make  excellent  material  for  the  micro- 
scopical study  of  starch  in  the  leaf. 


FIG.  123.— Leaf  of  Tropaeo- 
lum partly  covered  with 
Disks  of  Cork  and  ex- 
posed to  Sunlight. 


MINUTE   STRUCTURE   OF  LEAVES  171 

foliage  must  depend  on  the  kind  of  leaves,  the  tempera- 
ture of  the  air,  the  intensity  of  the  sunlight,  and  some 
other  circumstances.  Sunflower  leaves  and  pumpkin  or 
squash  leaves  have  been  found  to  manufacture  starch  at 
about  the  same  rate.  In  a  summer  day  fifteen  hours  long 
they  can  make  nearly  three-quarters  of  an  ounce  of  starch 
for  each  square  yard  of  leaf-surface.  A  full-grown  squash 
leaf  has  an  area  of  about  one  and  one-eighth  square  feet, 
and  a  plant  may  bear  as  many  as  100  leaves.  What  would 
be  the  daily  starch-making  capacity  of  such  a  plant  ? l 

183.  Assimilation.  —  From  the  starch  in  the  leaf,  grape- 
sugar  or  malt-sugar  is  readily  formed,  and  some  of  this  in 
turn  is  apparently  combined  on  the  spot  with  nitrogen, 
sulphur,  and  phosphorus.  These  elements  are  derived 
from  nitrates,  sulphates,  and  phosphates,  taken  up  in  a 
dissolved  condition  by  the  roots  of  the  plant  and  trans- 
ported to  the  leaves.  The  details  of  the  process  are  not 
understood,  but  the  result  of  the  combination  of  the 
sugars  or  similar  substances  with  suitable  (very  minute) 
proportions  of  nitrogen,  sulphur,  and  phosphorus  is  to 
form  complex  nitrogen  compounds.  These  are  not  pre- 
cisely of  the  same  composition  as  the  living  protoplasm 
of  plant-cells  or  as  the  reserve  proteids  stored  in  seeds 
(Sects.  14,  17),  stems  (Sect.  127),  and  other  parts  of 
plants,  but  are  readily  changed  into  protoplasm  or  proteid 
foods  as  necessity  may  demand. 

Assimilation  is  by  no  means  confined  to  leaves  ;  indeed, 
most  of  it,  as  above  suggested,  must  take  place  in  other 
parts  of  the  plant.  For  instance,  the  manufacture  of  the 
immense  amounts  of  cellulose,  of  cork,  and  of  the  com- 

1  See  Pfeffer's  Physiology  of  Plants,  translated  by  Ewart,  Vol.  I,  p.  324. 


172  FOUNDATIONS   OF  BOTANY 

pound  (ligniri)  characteristic  of  wood-fiber,  that  go  to  make 
up  the  main  bulk  of  a  large  tree  must  be  carried  on  in  the 
roots,  trunk,  and  branches  of  the  tree. 

184.  Digestive  Metabolism.  —  Plant-food  in  order  to  be 
carried  to  the  parts  where  it  is  needed  must  be  dissolved, 
and  this  dissolving  often  involves  a  chemical  change  and 
is  somewhat  similar  to  digestion  as  it  occurs  in  animals. 
The  newly  made  starch  in  the  leaf  must  be  changed  to  a 
sugar  or  other  substance  soluble  in  water  before  it  can  be 
carried  to  the  parts  of  the  plant  where  it  is  to  be  stored 
or  to  rapidly  growing  parts   where  it  is  to  be  used  for 
building  material.     On  the  other  hand,  starch,  oil,  and 
such  insoluble  proteids  as  are  deposited  in  the  outer  por- 
tion of  the  kernel  of  wheat  and  other  grains  are  extremely 
well  adapted  to  serve  as  stored  food,  but  on  account  of 
their  insoluble  nature  are  quite  unfit  to  circulate  through 
the  tissues  of  the  plant.     The  various  kinds  of  sugar  are 
not  well  adapted  for  storage,  since  they  ferment  easily  in 
the  presence   of   warmth  and   moisture  if   yeast-cells  or 
suitable  kinds  of  bacteria  are  present. 

Two  important  differences  between  starch-making  in 
the  green  parts  of  plants  and  the  non-constructive  or  the 
destructive  type  of  metabolism  should  be  carefully  noticed. 
These  latter  kinds  of  metabolism  go  on  in  the  dark  as 
well  as  in  the  light  and  do  not  add  to  the  total  weight 
of  the  plant. 

185.  Excretion  of  Water  and  Respiration.  —  Enough  has 
been  said  in  Sect.  174  concerning  the  former  of  these  pro- 
cesses.    Respiration,  or  breathing  in  oxygen  and  giving 
off  carbonic  acid  gas,  is  an  operation  which  goes  on  con- 
stantly in  plants,  as  it  does  in  animals,  and  is  necessary  to 


MINUTE   STRUCTURE   OF  LEAVES 


173 


their  life.  For,  like  animals,  plants  get  the  energy  with 
which  they  do  the  work  of  assimilation,  growth,  reproduc- 
tion, and  performing  their  movements  from  the  oxidation 
of  such  combustible  substances  as  oil,  starch,  and  sugar.1 

The  amount  of  oxy- 
gen absorbed  and  of  car- 
bonic acid  given  off  is, 
however,  so  trifling  com- 
pared with  the  amount 
of  each  gas  passing  in 
the  opposite  direction, 
while  starch-making  is 
going  on  in  sunlight, 
that  under  such  circum- 
stances it  is  difficult  to 
observe  the  occurrence 
of  respiration.  In  ordi- 
nary leafy  plants  the  FIG*  124.  —  Cross-Section  of  Stem  of  Marestail 
leaves  (through  their  (^™™)  with  Air-Passages,  a. 

stomata)  are  the  principal  organs  for  absorption  of  air,  but 
much  air  passes  into  the  plant  through  the  lenticels  of 
the  bark. 

In  partly  submerged  aquatics  especial  provisions  are 
found  for  carrying  the  air  absorbed  by  the  leaves  down  to 
the  submerged  parts.  This  is  accomplished  in  pond  lilies 
by  ventilating  tubes  which  traverse  the  leaf-stalks  length- 
wise. In  many  cases  such  channels  run  up  and  down  the 
stem  (Fig.  124). 

1  The  necessity  of  an  air  supply  about  the  roots  of  the  plant  may  be  shown 
by  filling  the  pot  or  jar  in  which  the  hydrangea  was  grown  for  the  transpi- 
ration experiment  perfectly  full  of  water  and  noting  the  subsequent  appear- 
ance of  the  plant  at  periods  twelve  to  twenty-four  hours  apart. 


1T4 


FOUNDATIONS   OF  BOTANY 


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MINUTE   STRUCTURE   OF  LEAVES  175 

187.  The  Fall  of  the  Leaf.  —  In  the  tropics  trees  retain 
most  of  their  leaves  the  year  round ;  a  leaf  occasionally 
falls,  but  no  considerable  portion  of  them  drops  at  any 
one  season.1  The  same  statement  holds  true  in  regard  to 
our  cone-bearing  evergreen  trees,  such  as  pines,  spruces, 
and  the  like.  But  the  impossibility  of  absorbing  soil-water 
when  the  ground  is  at  or  near  the  freezing  temperature 
(Exp.  XVII)  would  cause  the  death,  by  drying  up,  of 
trees  with  broad  leaf-surfaces  in  a  northern  winter.  And 
in  countries  where  there  is  much  snowfall,  most  broad- 
leafed  trees  could  not  escape  injury  to  their  branches  from 
overloading  with  snow,  except  by  encountering  winter 
storms  in  as  close-reefed  a  condition  as  possible.  For 
such  reasons  our  common  shrubs  and  forest  trees  (except 
the  cone-bearing,  narrow-leafed  ones  already  mentioned) 
are  mostly  deciduous,  that  is  they  shed  their  leaves  at  the 
approach  of  winter. 

The  fall  of  the  leaf  is  preceded  by  important  changes 
in  the  contents  of  its  cells. 

EXPERIMENT   XXXVII 

Does  the  Leaf  vary  in  its  Starch  Contents  at  Different  Seasons  ? 

Collect  in  early  summer  some  leaves  of  several  kinds  of  trees  and 
shrubs  and  preserve  them  in  alcohol.  Collect  others  as  they  are 
beginning  to  drop  from  the  trees  in  autumn  and  preserve  them  in 
the  same  way.  Test  some  of  each  lot  for  starch  as  described  in 
Sect.  181. 

What  does  the  result  indicate? 

Much  of  the  sugary  and  protoplasmic  contents  of  the 
leaf  disappears  before  it  falls.  These  valuable  materials 

1  Except  where  there  is  a  severe  dry  season. 


176  FOUNDATIONS  OF  BOTANY 

have  been  absorbed  by  the  branches  and  roots,  to  be  used 
again  the  following  spring. 

The  separation  of  the  leaf  from  the  twig  is  accomplished 
by  the  formation  of  a  layer  of  cork  cells  across  the  base  of 
the  petiole  in  such  a  way  that  the  latter  finally  breaks  off 
across  the  surface  of  the  layer.  A  waterproof  scar  is  thus 
already  formed  before  the  removal  of  the  leaf,  and  there  is 
no  waste  of  sap  dripping  from  the  wound  where  the  leaf- 
stalk has  been  removed,  and  no  chance  for  moulds  to 
attack  the  bark  or  wood  and  cause  it  to  decay.  In  com- 
pound leaves  each  leaflet  may  become  separated  from  the 
petiole,  as  is  notably  the  case  with  the  horse-chestnut  leaf 
(Fig.  102).  In  woody  monocotyledons,  such  as  palms,  the 
leaf-stalks  do  not  commonly  break  squarely  off  at  the  base, 
but  wither  and  leave  projecting  stumps  on  the  stem 
(Plate  VI). 

The  brilliant  coloration,  yellow,  scarlet,  deep  red,  and 
purple,  of  autumn  leaves  is  popularly  but  wrongly  sup- 
posed to  be  due  to  the  action  of  frost.  It  depends  merely 
on  the  changes  in  the  chlorophyll  grains  and  the  liquid 
cell-contents  that  accompany  the  withdrawal  of  the  proteid 
material  from'  the  tissues  of  the  leaf.  The  chlorophyll 
turns  into  a  yellow  insoluble  substance  after  the  valuable 
materials  which  accompany  it  have  been  taken  away,  and 
the  cell  sap  at  the  same  time  may  turn  red.  Frost  per- 
haps hastens  the  break-up  of  the  chlorophyll,  but  individual 
trees  often  show  bright  colors  long  before  the  first  frost, 
and  in  very  warm  autumns  most  of  the  changes  in  the  foli- 
age may  come  about  before  there  has  been  any  frost. 

188.    Tabular  Review  of  Experiments. 
[Continue  the  table  from  Sect.  128.] 


PLATE  VI.  —  Fan  Palms 


MINUTE  STRUCTURE  OF  LEAVES        177 

189.  Review  Summary  of  Minute  Structure  of  Leaves.1 

General  structure,  distribution  of 
parenchyma,  andprosenchyma 

Layers  of  tissue  seen  on  a  cross- 
section  

Structure  of  epidermis      .     .     . 

Structure  of  stomata    .     .     .     . 

Distribution  of  stomata    .     .     . 

Structure  and  distribution  of 
chlorophyll  bodies  .  .  .  , 

190.  Review  Summary  of  Functions  of  Leaves. 

nbro-vascular  bundles 
epidermis  .... 
stomata      .... 

Principal  uses  of J  air  spaces  .     .     .     . 

palisade-cells  .     .     ... 
spongy  parenchyma 
waxy  coating .     .     . 
hairs 

Substances  received  by  the  leaf  .  {  from  the  air  •     •     • 

[  from  the  soil . 

Substances  manufactured  by  the  leaf  .     . 

Substances  given  off  by  the  leaf      .    i: ," .      {  ?nto  the  air     •     •     • 

[  into  the  stem 

Mineral  substances  accumulated  in  the  leaf 
Statistics  in  regard  to  transpiration     .     . 
Statistics  in  regard  to  starch-making  .     . 

1  Illustrate  with  sketches  and  diagrams. 


CHAPTER    XII 
PROTOPLASM    AND    ITS    PROPERTIES 

191.  The   Cell  in  its   Simplest  Form.  —  Sufficient  has 
been  said  in  the  preceding  chapters,  and  enough  tissues 
have  been  microscopically  studied,  to  make  it  pretty  clear 
what  vegetable  cells,  as  they  occur  in  flowering  plants, 
are  like.     In  Chapter  XI,  leaf-cells  have  been  taken  for 
granted  and  their  work  described  in  some  detail.     Before 
going  further,  it  is  worth  while,  to  consider  the  structure 
of  an  individual  cell,  and  to  see  of  what  kinds  of  activity 
it  is  capable. 

In  studying  the  minute  anatomy  of  bark,  wood,  pith, 
and  other  tissues  the  attention  is  often  directed  to  the 
cell-wall  without  much  regard  to  the  nature  of  the  cell- 
contents.  Yet  the  cell-wall  is  not  the  cell,  any  more  than 
the  lobster  shell  or  the  crayfish  shell  is  the  lobster  or  the 
crayfish.  The  contained  protoplasm  with  its  nucleus  is  the 
cell.1  The  cell  reduced  to  its  lowest  terms  need  not  have 
a  cell-wall,  but  may  consist  simply  of  a  mass  of  proto- 
plasm, usually  containing  a  portion  of  denser  consistency 
than  the  main  bulk,  known  as  the  nucleus. 

Such  cells,  without  a  cell-wall,  are  not  common  in  the  vege- 
table world,  but  are  frequently  encountered  among  animals. 

192.  The  Slime  Moulds.2  —  One  of  the  best  examples  of 
masses  of  naked  protoplasm  leading  an  individual  existence 

1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  pp.  21-51. 

2  Strasburger,  Noll,  Schenk,  and  Schimper's  Text-Book  of  Botany,  pp.  50-52 
and  302-305. 

178 


PROTOPLASM  AND  ITS  PROPERTIES       179 

is  found  in  the  slime  moulds,  which  live  upon  rotten  tan 
bark,  decaying  wood,  and  so  on.  These  curious  organ- 
isms have  so  many  of  the  characteristics  both  of  animals 
and  of  plants  that  they  have  been  described  in  zoologies 
under  the  former  title  and  in  botanies  under  the  latter 
one.  Perhaps  it  would  not  really  be  so  absurd  a  state- 
ment as  it  might  seem,  to  say  that  every  slime  mould  leads 
the  life  of  an  animal  during  one  period  of  its  existence  and 
of  a  plant  at  another  period.  At  any  rate,  whatever  their 
true  nature,  these  little  masses  of  unenclosed  protoplasm 
illustrate  admirably  some  of  the  most  important  properties 
of  protoplasm.  Slime  moulds  spring  from  minute  bodies 
called  spores  (Fig.  125,  a)  which  differ  from  the  seeds  of 
seed-plants  not  only  in  their  microscopic  size  but  still 
more  in  their  lack  of  an  embryo.  The  spores  of  slime 
moulds  are  capable,  when  kept  dry,  of  preserving  for 
many  years  their  power  of  germination,  but  in  the  pres- 
ence of  moisture  and  warmth  they  will  germinate  as  soon 
as  they  are  scattered.  During  the  process  of  germination 
the  spore  swells,  as  shown  at  5,  and  then  bursts,  discharging 
its  protoplasmic  contents,  as  seen  at  c  and  d.  This  in  a 
few  minutes  lengthens  out  and  produces  at  one  end  a  hair- 
like  cilium,  as  shown  at  e,f,  g.  These  ciliated  bodies  are 
called  swarmspores,  from  their  power  of  swimming  freely 
about  by  the  vibrating  motion  of  the  cilia.  Every  swarm- 
spore  has  at  its  ciliated  end  a  nucleus,  and  at  the  other  end 
a  bubble-like  object  which  gradually  expands,  quickly  dis- 
appears, and  then  again  expands.  This  contractile  vacuole 
is  commonly  met  with  in  animalcules,  and  increases  the 
likeness  between  the  slime  moulds  and  many  microscopic 
animals.  The  next  change  of  the  swarmspores  is  into  an 


180 


FOUNDATIONS   OF  BOTANY 


Amoeba  form  (so  called  from  one  of  the  most  interesting  and 
simplest  of  animals,  the  Amoeba,  found  on  the  surface  of 


FlG.  125.  —  A  Slime  Mould,    (a-m,  inclusive,  x  540  times,  n  x  90  times.) 

mud  and  the  leaves  of  water  plants).  In  this  condition, 
as  shown  at  h,  i,  k,  the  spores  creep  about  over  the  sur- 
face of  the  decaying  vegetable  material  on  which  the 


PROTOPLASM  AND  ITS  PROPERTIES       181 

slime  moulds  live.  Their  movement  is  caused  by  a  thrust- 
ing out  of  the  semi-liquid  protoplasm  on  one  side  of  the 
mass,  and  a  withdrawal  of  its  substance  from  the  other 
side.  At  length  many  amoeba-shaped  bodies  unite,  as  at  Z, 
to  form  a  larger  mass,  w,  which  finally  increases  to  the 
protoplasmic  network  shown  at  n.  This  eventually  col- 
lects into  a  roundish  or  egg-shaped  firm  body,  inside  of 
which  a  new  crop  of  spores  is  produced.  It  is  not  easy  to 
trace  the  manner  in  which  the  nourishment  of  these  simple 
plants  is  taken.  Probably  they  absorb  it  from  the  decay- 
ing matter  upon  which  they  live  during  their  amoeba-like 
period,  and  after  they  have  formed  the  larger  masses,,  n. 
193.  Characteristics  of  Living  Protoplasm.1  —  The  behav- 
ior of  the  slime  moulds  during  their  growth  and  transfor- 
mations, as  just  outlined,  affords  a  fair  idea-  of  several  of 
the  remarkable  powers  which  belong  to  living  protoplasm, 
which  have  been  summed  up  as  follows : 

(1)  The  power  to  take  up  new  material  into  its  own 
substance  (selective  absorption).     This  is  not  merely  a  proc- 
ess of  soaking  up  liquids,  such  as  occurs  when  dry  earth 
or  a  sponge  is  moistened.     The  protoplasmic  lining  of  a 
root-hair,  for  example,  selects  from  the  soil-water  some 
substances  and  rejects  others  (Sect.  65). 

(2)  The  ability  to  change  certain  substances  into  others 
of  different  chemical  composition  (metabolism,  Sect.  176). 
Carbon  dioxide  and  water,    losing  some   oxygen  in   the 
process,  are  combined  into  starch;  starch  is  changed  into 
various  kinds  of  sugar  and  these  back  into  starch  again ; 
starch  becomes  converted  into  vegetable  acids,  into  cellu- 
lose, or  into  oil ;  or  the  elements  of  starch  are  combined 

1  See  Huxley's  Essays,  Vol.  I,  essay  on  "  The  Physical  Basis  of  Life." 


182  FOUNDATIONS  OF  BOTANY 

with  nitrogen  to  make  various  proteid  compounds,  either 
for  immediate  use  or  for  reserve  food.  Many  other  com- 
plicated transformations  occur. 

(3)  The  power  to  cast  off   waste  or  used-up   material 
(excretion).     Getting  rid  of  surplus  water  (Sect.  174)  and 
of  oxygen  (Sect.  178)  constitutes  a  very  large  part  of  the 
excretory  work  of  plants. 

(4)  The  capacity  for  growth  and  the  production  of  off- 
spring (reproduction).     These  are  especially  characteristic 
of  living  protoplasm.     It  is  true  that  non-living  objects 
may  grow  in  a  certain  sense,  as  an  icicle  or  a  crystal  of 
salt  or  of  alum  in  a  solution  of  its  own  material  does. 
But  growth  by  the  process  of  taking  suitable  particles 
into  the  interior  of  the  growing  substance  and  arranging 
them  into  an  orderly  structure  (Fig.  126)  is  possible  only 
in  the  case  of  live  protoplasm. 

(5)  The  possession  of  the  power  of  originating  move- 
ments  not  wholly  and  directly  caused  by  any  external 
impulse    (automatic  movements).     Such,   for  instance,  are 
the  lashing  movements  of  the  cilia  of  the   swarmspores 
of   slime  moulds,  or  the  slow  pendulum  movements  of 
Oscillatoria  (Sect.  269),  or  the  slow  vibrating  movements 
of  the   stipules  of   the  "  telegraph   plant "  (Desmodium), 
not  uncommon  in  greenhouses. 

(6)  The  power  of  shrinking  or  closing  up  (contractility). 
This  is  illustrated  by  the  action  of  the  contractile  vacuole 
of  the  slime  moulds  and  of  many  animalcules  and  by  all 
the  muscular  movements  of  animals. 

(7)  Sensitiveness  when  touched  or  otherwise  disturbed, 
for   instance,   by  a   change   of   light   or   of   temperature 
(irritability). 


PROTOPLASM  AND  ITS  PROPERTIES 


183 


194.  Nature  and  Occurrence  of  Irritability  in  Plants.1  — 
Mention  has  already  been  made  of  the  fact  that  certain 
parts  of  plants  respond  to  suitable  stimuli  that  is  exciting 


FIG.  126.  —Protoplasm  in  Ovule  and  Fruit  of  Snowberry  (Symphoricarpus 

racemosus). 
A,  cells  from  ovule,  x  340 ;  JB,  cells  from  an  ovule  further  developed,  x  340 ;  C,  D, 

cells  from  pulp  of  fruit,  x  no  ;  n,  nucleus  ;  p,  protoplasm  ;  s,  cell-sap. 
In  the  young  and  rapidly  growing  cells,  A  and  B,  the  cell-sap  is  not  present,  or 

present  only  in  small  quantities,  while  in  the  older  cells,  C  and  D,  it  occupies 

a  large  portion  of  the  interior  of  the  cell. 

causes.     Geotropic  movements  (Sect.  70)  are  due  to  the 
stimulating    effect    of    gravitation    on    roots    or    shoots. 

1  See  Strasburger,  Noll,  Schenk,  and  Schimper's  Text-Book  of  Botany, 
pp.  160-162  and  269-274. 


184 


FOUNDATIONS   OF  BOTANY 


These  movements  are  due  to  unequal  growth  induced  in 
the  younger  portions  of  the  plant  by  the  action  of  gravi- 
£^  tation  upon  it.  Other  movements  (of 

yl  ordinary  foliage  leaves,  of  the  floral  leaves 

of  many  flowers,  and  of  other  parts  of  a 
few  flowers)  are  produced  by  changes  in 
the  distention  or  turgescence  of  some  of  the 
cells  in  the  organs  which  move  and  have 
nothing  to  do  with  growth.  The  closing 
of  the  leaves  of  insect-catching  plants  is 
briefly  described  in  Sect.  410,  and  the 
"  sleep "  of  leaves,  due  to  movements  of 
the  pulvini,  was  described  in  Sect.  152. 
A  few  facts  in  regard  to  the  opening  and 
closing  of  flowers  will  be  found  in 
Sect.  440. 

The  stimuli  which  cause  movements  of 
leaves  or  of  the  irritable  parts  of  flowers 
are  of  several  kinds.  Light  is  the  main 
cause  which  induces  leaves  to  open  from 
their  night  position  to  that  usual  in  the 
daytime.  In  the  case  of  flowers,  it  is 
sometimes  light  and  sometimes  warmth 
FIG.  127.  —  stinging  which  causes  them  to  open.  Leaves  which 

Hair  of  Nettle,  with  .  ,  ,  ^  , 

Nucleus.    (Much   catch  insects  may   be  made  to    close    by 
magnified.)  The  ar-   touching   them,  but   the  sensitive-plants, 

rows  show  the  direc- 
tion of  the  currents    of  which  there  are  several  kinds  found  in 

the  United  States,  and  a  much  more  sensi- 
tive one  in  tropical  America,  all  fold  their  leaflets,  on 
being  touched,  into  the  same  position  which  they  assume 
at  night. 


PROTOPLASM  AND  ITS  PROPERTIES       185 

195.  Circulation  of  Protoplasm.  —  When  confined  by  a 
cell-wall,  protoplasm  often  manifests  a  beautiful  and  con- 
stant rotating  movement,  traveling  incessantly  up  one 
side  of  the  cell  and  down  the  other.1  A  more  complicated 
motion  is  the  circulation  of  protoplasm,  shown  in  cells  of 
the  jointed  blue  hairs  in  the  flower  of  the  common  spider- 
wort  and  in  the  stinging  hairs  of  the  nettle  (Fig.  127). 
The  thin  cell- wall  of  each  hair  is  lined  with  a  protoplasmic 
layer  in  which  are  seen  many  irregular,  thread-like  cur- 
rents, marked  by  the  movements  of  the  granules,  of  which 
the  protoplasmic  layer  is  full. 

1  See  Huxley  and  Martin's  Elementary  Biology,  under  Chara. 


CHAPTER    XIII 


INFLORESCENCE,    OR    ARRANGEMENT    OF   FLOWERS 
ON    THE    STEM 

196.  Regular  Positions  for  Flower-Buds.  —  Flower-buds, 
like  leaf-buds,  occur  regularly  either  in  the  axils  of  leaves 
or  at  the  end  of  the  stem  or  branch  and  are  therefore 
either  axillary  or  terminal. 

197.  Axillary    and    Solitary    Flowers;     Indeterminate 
Inflorescence.  —  The    simplest    possible    arrangement   for 

flowers  which  arise  from  the  axils  of 
leaves  is  to  have  a  single  flower  spring 
from  each  leaf -axil.  Fig.  128  shows 
how  this  plan  appears  in  a  plant  with 
opposite  leaves.  As  long  as  the  stem 
continues  to  grow,  the  production  of  new 
leaves  may  be  followed  by  that  of  new 


,P 


FIG.  128.  — Axillary  and 
Solitary  Flowers  of 
Pimpernel. 


FIG.  129.  —  Raceme    of 
Common  Red  Currant. 
p,  peduncle  ;  p',  pedicel ;  br,  bract. 


flowers.  Since  there  is  no  definite  limit  to  the  number 
of  flowers  which  may  appear  in  this  way,  the  mode  of 
flowering  just  described  (with  many  others  of  the  same 
general  character)  is  known  as  indeterminate  inflorescence. 

186 


ARRANGEMENT  OF  FLOWERS  ON  THE  STEM   187 


FIG.  130.  —  Simple  Umbel  of  Cherry. 


198.    The  Racemes  and  Related  Forms.  —  If  the  leaves 
along  the  stem  were  to  become  very  much  dwarfed  and  the 

flowers  brought  closer  together, 
as  they  frequently  are,  a  kind 
of  flower-cluster  like  that  of  the 
currant  (Fig.  129)  or  the  lily- 
of-t he-valley  would  result.  Such 
an  inflorescence  is  called  a  ra- 
ceme; the  main  flower-stalk  is 
known  as  the  peduncle  ;  the  little 
individual  flower-stalks  are  pedi- 
cels, and  the  small,  more  or 
less  scale -like  leaves  of  the 
peduncle  are  bracts.1 
Frequently  the  lower  pedicels  of  a  cluster  on  the 
general  plan  of  the  raceme  are  longer  than  the  upper 
ones  and  make  a  some- 
what flat-topped  cluster, 
like  that  of  the  hawthorn, 
the  sheep  laurel,  or  the 
trumpet  creeper.  This 
is  called  a  corymb. 

In  many  cases,  for  ex- 
ample the  parsnip,  the 
Sweet  Cicely,  the  gin- 
seng, and  the  cherry,  a 
group  of  pedicels  of 
nearly  equal  length 


FIG.  131.  — Catkins  of  Willow. 
A,  staminate  flowers  ;  JS,  pistillate  flowers. 


1  It  is  hardly  necessary  to  say  that  the  teacher  will  find  it  better  in  every 
way,  if  material  is  abundant,  to  begin  the  study  of  flower-clusters  with  the 
examination  of  typical  specimens  by  the  class. 


188 


FOUNDATIONS  OF  BOTANY 


spring    from   about   the    same    point.      This    produces    a 
flower-cluster  called  the  umbel  (Fig.  130). 

199.  Sessile  Flowers  and  Flower-Clusters.  —  Often  the 
pedicels  are  wanting,  or  the  flowers  are  sessile,  and  then 
a  modification  of  the  raceme  is  produced  which  is  called 
a  spike,  like  that  of  the  plantain  (Fig.  132).  The 
willow,  alder,  birch,  poplar,  and  many  other  common 
trees  bear  a  short,  flexible,  rather  scaly  spike  (Fig. 
131),  which  is  called  a  catkin. 

The  peduncle  of  a  spike  is  -often  so  much  short- 
ened as  to  bring  the  flowers  into  a  somewhat  globu- 
lar mass.    This  is  called  a  head  (Fig.  132).    Around 
the  base   of  the  head  usually 
occurs  a  circle  of  bracts  known 
as  the    involucre.      The    same 
name  is  given  to  a  set  of  bracts 
which  often  surround  the  bases 
of  the  pedicels  in  an  umbel. 

200.  The  Composite  Head.  — 
The  plants  of  one  large  group, 
of  which  the  dandelion,  the 
daisy,  the  thistle,  and  the  sun- 
flower are  well-known  members,  bear  their  flowers  in 
close  involucrate  heads  on  a  common  receptacle.  The 
whole  cluster  looks  so  much  like  a  single  flower  that  it  is 
usually  taken  for  one  by  non-botanical  people.  In  many 
of  the  largest  and  most  showy  heads,  like  that  of  the 
sunflower  and  the  daisy,  there  are  two  kinds  of  flowers, 
the  ray-flowers,  around  the  margin,  and  the  tubular  disk- 
flowers  of  the  interior  of  the  head  (Fig.  133).  The  early 
botanists  supposed  the  whole  flower-cluster  to  be  a  single 


FIG.  132.  —  Spike  of  Plantain  and 
Head  of  Red  Clover. 


ARRANGEMENT   OF  FLOWERS   ON  THE   STEM       189 


B 


FIG.  133.— Head  of  Yarrow. 

A,  top  view.  (Magnified.)  B,  lengthwise  section.  (Magnified.)  re,  receptacle  ;  i, 
involucre  ;  r,  ray-flowers  ;  d,  disk-flowers  ;  c,  corolla  ;  s,  stigma ;  ch,  chaff, 
or  bracts  of  receptacle. 


FIG. 134. 
Panicle  of  Oat. 


FIG.  135.  — Compound  Umbel 
of  Carrot. 


190 


FOUNDATIONS    OF   BOTANY 


compound  flower.  This  belief  gave  rise  to  the  name  of 
one  family  of  plants,  Compositoe,  that  is,  plants  with  com- 
pound flowers.  In  such  heads  as  those  of  the  thistle,  the 
cud  weed,  and  the  everlasting  there  are  no  ray-flowers, 
and  in  others,  like  those  of  the  dandelion  and  the  chicory, 
all  the  flowers  are  ray-flowers. 

201.    Compound  Flower-Clusters.  —  If  the  pedicels  of  a 
raceme  branch,  they  may  produce  a  compound  raceme,  or 


? 


A  B  C  &£ 

FIG.  136.  — Diagrams  of  Inflorescence. 
A,  panicle  ;  B,  raceme  ;  C,  spike  ;  D,  umbel ;  E,  head. 

panicle,  like  that  of  the  oat  (Fig.  134).1  Other  forms  of 
compound  racemes  have  received  other  names. 

An  umbel  may  become  compound  by  the  branching  of 
its  flower-stalks  (Fig.  135),  each  of  which  then  bears  a 
little  umbel,  an  umbellet. 

202.  Inflorescence  Diagrams.  —  The  plan  of  inflorescence 
may  readily  be  indicated  by  diagrams  like  those  of  Fig.  136. 

The  student  should  construct  such  diagrams  for  some  rather  corn- 
plicated  flower-clusters,  like  those  of  the  grape,  horse-chestnut  or 
buckeye,  hardback,  vervain,  or  many  grasses. 

1  Panicles  may  also  be  formed  by  compound  cymes  (see  Sect.  204). 


ARRANGEMENT   OF  FLOWERS   ON  THE   STEM        191 


203.  Terminal    Flowers ;    Determinate   Inflorescence.  - 
The  terminal  bud  of  a  stem  may  be  a  flower-bud.     In  this 
case  the  direct  growth  of  the  stem  is  stopped  or  deter- 
mined by  the  appearance  of  the  flower ;  hence  such  plants 
are  said  to  have  a  determinate  inflorescence.     The  simplest 
possible  case  of  this  kind  is  that 

in  which  the  stem  bears  but  one 
flower  at  its  summit. 

204.  The  Cyme. — Very  often 
flowers  appear  from  lateral  (axil- 
lary) buds,  below  the  terminal 
flower,  and  thus  give  rise  to  a 
flower-cluster  called  a  cyme. 
This  may  have  only  three  flowers, 
and  in  that  case  would  look  very 
much  like   a   three-flowered 
umbel.      But   in    the    raceme, 
corymb,  and  umbel  the  order  of 
flowering  is  from  below  upward, 
or  from  the  outside  of  the  clus- 
ter inward,  because  the  lowest  or  the  outermost  flowers 
are  the  oldest,  while  in  determinate  forms  of  inflorescence 
the  central  flower  is  the  oldest,  and  therefore  the  order  of 
blossoming  is  from  the  center  outwards.     Cymes  are  very 
commonly  compound,  like  those  of  the  elder  and  of  many 
plants  of  the  pink  family,  such  as  the  Sweet  William  and 
the  mouse-ear  chickweed  (Fig.  137).     They  may  also,  as 
already  mentioned,  be    panicled,  thus    making    a  cluster 
much  like  Fig.  136,  A. 


FIG.  137.  —  Compound  Cyme  of 

Mouse-Ear  Chickweed. 
t,  the  terminal  (oldest)  flower. 


CHAPTER   XIV 
THE    STUDY   OF   TYPICAL   FLOWERS 

(Only  one  of  the  three  flowers  described  to  be  studied  by  aid  of  these 
directions.) 

205,  The  Flower  of  the  Trillium.  —  Cut  off  the  flower-stalk  rather 
close  to  the  flower;  stand  the  latter,  face  down,  on  the  table,  and 
draw  the  parts  then  shown.  Label  the  green  leaf-like  parts  sepals, 
and  the  white  parts,  which  alternate  with  these,  petals.  Turn  the 
flower  face  up,  and  make  another  sketch,  labeling  the  parts  as  before, 
together  with  the  yellow  enlarged  extremities  or  anthers  of  the  stalked 
organs  called  stamens. 

Note  and  describe  the  way  in  which  the  petals  alternate  with  the 
sepals.  Observe  the  arrangement  of  the  edges  of  the  petals  toward 
the  base,  — how  many  with  both  edges  outside  the  others,  how  many 
with  both  edges  inside,  how  many  with  one  edge  in  and  one  out. 

Note  thja  veining  of  both  sepals  and  petals,  more  distinct  in 
which  set?1 

Pull  off  a  sepal  and  make  a  sketch  of  it,  natural  size  ;  then  remove 
a  petal,  flatten  it  out,  and  sketch  it,  natural  size. 

Observe  that  the  flower-stalk  is  enlarged  slightly  at  the  upper  end 
into  a  rounded  portion,  the  receptacle,  on  which  aft  the  parts  of  the 
flower  rest. 

Note  how  the  six  stamens  arise  from  the  receptacle  and  their 
relations  to  the  origins  of  the  petals.  Remove  the  remaining  petals 

1  In  flowers  with  delicate  white  petals  the  distribution  of  the  fibro-vascular 
bundles  in  these  can  usually  be  readily  shown  by  standing  the  freshly  cut  end 
of  the  peduncle  in  red  ink  for  a  short  time,  until  colored  veins  begin  to  appear 
in  the  petals.  The  experiment  succeeds  readily  with  apple,  cherry,  or  plum 
blossoms ;  with  white  gilliflower  the  coloration  is  very  prompt.  Lily-of-the- 
valley  is  perhaps  as  interesting  a  flower  as  any  on  which  to  try  the  experi- 
ment, since  the  well-defined  stained  stripes  are  separated  by  portions  quite 
free  from  stain,  and  the  pistils  are  also  colored. 

192 


THE   STUDY   OF  TYPICAL  FLOWERS  193 

(cutting  them  off  near  the  bottom  with  a  knife),  and  sketch  the  sta- 
mens, together  with  the  other  object,  the  pistil,  which  stands  in  the 
center. 

Cut  off  one  stamen,  and  sketch  it  as  seen  through  the  magnifying 
glass.  Notice  that  it  consists  of  a  greenish  stalk,  the  f  lament,  and 
a  broader  portion,  the  anther  (Fig.  149).  The  latter  is  easily  seen 
to  contain  a  prolongation  of  the  green  filament,  nearly  surrounded 
by  a  yellow  substance.  In  the  bud  it  will  be  found  that  the  anther 
consists  of  two  long  pouches  or  anther-cells,  which  are  attached  by 
their  whole  length  to  the  filament,  and  face  inward  (towards  the 
center  of  the  flower).  When  the  flower  is  fairly  open,  the  anther- 
cells  have  already  split  down  their  margins,  and  are  discharging  a 
yellow,  somewhat  sticky  powder,  the  pollen. 

Examine  one  of  the  anthers  with  the  microscope,  using  the  two- 
inch  objective,  and  sketch  it.  •  %  ' 

Cut  away  all  the  stamens,  and  sketch  the  pistil.  It  consists  of  a 
stout  lower  portion,  the  ovary,  which  is  six-ridged  or  angled,  and 
which  bears  at  its  summit  three  slender  stigmas. 

In  another  flower,  which  has  begun  to  wither  (and  in  which  the 
ovary  is  larger  than  in  a  newly  opened  flower),  cut  the  ovary  across 
about  the  middle,  and  try  to  make  out  with  the  magnifying  glass 
the  number  of  chambers  or  cells  which  it  contains.  Examine  the 
cross-section  with  the  two-inch  objective ;  sketch  it,  and  note  partic- 
ularly the  appearance  and  mode  of  attachment  of  the  undeveloped 
seeds  or  ovules  with  which  it  is  filled.  Make  a  vertical  section  of 
another  rather  mature  ovary,  and  examine  this  in  the  same  way. 

Using  a  fresh  flower*,  construct  a  diagram  to  show  the  relation  of 
the  parts  on  an  imaginary  cross-section,  as  illustrated  in  Fig.  157. 1 
Construct  a  diagram  of  a  longitudinal  section  of  the  flower,  on  the 
general  plan  of  those  in  Fig.  155,  but  showing  the  contents  of  the 
ovary. 

Make  a  tabular  list  of  the  parts  of  the  flower,  beginning  with  the 
sepals,  giving  the  order  of  parts  and  number  in  each  set. 

1  It  is  important  to  notice  that  such  a  diagram  is  not  a  picture  of  the  section 
actually  produced  by  cutting  through  the  flower  crosswise  at  anyone  level, 
but  that  it  is  rather  a  projection  of  the  sections  through  the  most  typical  part 
of  each  of  the  floral  organs. 


194  FOUNDATIONS   OF   BOTANY 

206.  The  Flower  of  the  Tulip.1  —  Make  a  diagram  of  a  side  view 
of  the  well-opened  flower,  as  it  appears  when  standing  in  sunlight. 
Observe  that  there  is  a  set  of  outer  flower-leaves  and  a  set  of  inner 
ones.2  Label  the  outer  set  sepals  and  the  inner  set  petals.  In  most 
flowers  the  parts  of  the  outer  set  are  greenish,  and  those  of  the  inner 
set  of  some  other  color.  It  is  often  convenient  to  use  the  name 
perianth,  meaning  around  the  flower,  for  the  two  sets  taken  together. 
Note  the  white  waxy  bloom  on  the  outer  surface  of  the  outer  seg- 
ments of  the  perianth.  What  is  the  use  of  this  ?  Note  the  manner 
in  which  the  inner  segments  of  the  perianth  arise  from  the  top  of  the 
peduncle  and  their  relation  to  the  points  of  attachment  of  the  outer 
segments.  In  a  flower  not  too  widely  opened,  note  the  relative  posi- 
tion of  the  inner  segments  of  the  perianth,  how  many  wholly  outside 
the  other  two,  how  many  wholly  inside,  how  many  with  one  edge  in 
and  one  edge  out. 

Remove  one  of  the  sepals  by  cutting  it  off  close  to  its  attachment 
to  the  peduncle,  and  examine  the  veining  by  holding  it  up  in  a  strong 
light  and  looking  through  it.  Make  a  sketch  to  show  the  general 
outline  and  the  shape  of  the  tip. 

Examine  a  petal  in  the  same  way,  and  sketch  it. 

Cut  off  the  remaining  portions  of  the  perianth,  leaving  about  a 
quarter  of  an  inch  at  the  base  of  each  segment.  Sketch  the  upright, 
triangular,  pillar-like  object'  in  the  center,  label  it  pistil,  sketch  the 
organs  which  spring  from  around  its  base,  and  label  these  stamens. 

Note  the  fact  that  each  stamen  arises  from  a  point  just  above  and 
within  the  base  of  a  segment  of  the  perianth.  Each  stamen  consists 
of  a  somewhat  conical  or  awl-shaped  portion  below,  the  filament,  sur- 
mounted by  an  ovate  linear  portion,  the  anther.  Sketch  one  of  the 
stamens  about  twice  natural  size  and  label  it  x  2.  Is  the  attach- 
ment of  the  anther  to  the  filament  such  as  to  admit  of  any  nodding 
or  twisting  movement  of  the  former  V  In  a  young  flower,  note  the 
two  tubular  pouches  or  anther-cells  of  which  the  anther  is  composed, 
and  the  slits  by  which  these  open.  Observe  the  dark-colored  pollen 

1  Tulipa  Gesneriana.    As  the  flowers  are  rather  expensive,  and  their  parts 
are  large  and  firm,  it  is  not  absolutely  necessary  to  give  a  flower  to  each  pupil, 
but  some  may  be  kept  entire  for  sketching  and  others  dissected  by  the  class. 
All  the  flowers  must  be  single. 

2  Best  seen  in  a  flower  which  is  just  opening. 


THE   STUDY   OF   TYPICAL  FLOWERS  195 

which  escapes  from  the  anther-cells  and  adheres  to  paper  or  to  the 
fingers.  Examine  a  newly  opened  anther  with  the  microscope,  using 
the  two-inch  objective,  and  sketch  it. 

Cut  away  all  the  stamens  and  note  the  two  portions  of  the  pistil, 
a  triangular  prism,  the  ovary,  and  three  roughened  scroll-like  objects 
at  the  top,  the  three  lobes  of  the  stigma.  Make  a  sketch  of  these 
parts  about  twice  natural  size,  and  label  them  x  2.  Touch  a  small 
camel's-hair  pencil  to  one  of  the  anthers,  and  then  transfer  the  pollen 
thus  removed  to  the  stigma.  This  operation  is  merely  an  imitation 
of  the  work  done  by  insects  which  visit  the  flowers  out  of  doors. 
Does  the  pollen  cling  readily  to  the  rough  stigrnatic  surface  ?  Examine 
this  adhering  pollen  with  the  two-inch  objective,  and  sketch  a  few 
grains  of  it,  together  with  the  bit  of  the  stigma  to  which  it  clings. 
Compare  this  drawing  with  Fig.  162.  Make  a  cross-section  of  the 
ovary  about  midway  of  its  length,  and  sketch  the  section  as  seen 
through  the  magnifying  glass.  Label  the  three  chambers  shown 
cells  of  the  ovary  l  or  locules,  and  the  white  egg-shaped  objects  within 
ovules.2 

Make  a  longitudinal  section  of  another  ovary,  taking  pains  to 
secure  a  good  view  of  the  ovules,  and  sketch  as  seen  through  the 
magnifying  glass. 

Making  use  of  the  information  already  gained  and  the  cross- 
section  of  the  ovary  as  sketched,  construct  a  diagram  of  a  cross- 
section  of  the  entire  flower  on  the  same  general  plan  as  those  shown 
in  Fig.  157.3 

Split  a  flower  lengthwise,4  and  construct  a  longitudinal  section  of 
the  entire  flower  on  the  plan  of  those  shown  in  Fig.  155,  but  showing 
the  contents  of  the  ovary. 

207.  The  Flower  of  the  Buttercup.  —  Make  a  diagram  of  the 
mature  flower  as  seen*  in  a  side  view,  looking  a  little  down  into  it. 
Label  the  pale  greenish-yellow,  hairy,  outermost  parts  sepals,  and 

1  Notice  that  the  word  cell  here  means  a  comparatively  large  cavity,  and  is 
not  used  in  the  same  sense  in  which  we  speak  of  a  wood-cell  or  a  pith-cell. 

2  The  section  will  be  more  satisfactory  if  made  from  an  older  flower,  grown 
out  of  doors,  from  which  the  perianth  has  fallen.     In  this  case  label  the  con- 
tained objects  seeds. 

3  Consult  also  the  footnote  on  p.  193. 

4  One  will  do  for  an  entire  division  of  the  class. 


196  FOUNDATIONS   OF   BOTANY 

the  larger  bright  yellow  parts  above  and  within  these  petals,  and 
the  yellow-knobbed  parts  which  occupy  a  good  deal  of  the  interior 
of  the  flower  stamens. 

Note  the  difference  in  the  position  of  the  sepals  of  a  newly 
opened  flower  and  that  of  the  sepals  of  a  flower  which  has  opened  as 
widely  as  possible.  Note  the  way  in  which  the  petals  are  arranged 
in  relation  to  the  sepals.  In  an  opening  flower  observe  the  arrange- 
ment of  the  edges  of  the  petals,  how  many  entirely  outside  the 
others,  how  many  entirely  inside,  how  many  with  one  edge  in  and 
the  other  out. 

Cut  off  a  sepal  and  a  petal,  each  close  to  its  attachment  to  the 
flower ;  place  both,  face  down,  on  a  sheet  of  paper,  and  sketch  about 
twice  the  natural  size  and  label  it  x  2.  Describe  the  difference  in 
appearance  between  the  outer  and  the  inner  surface  of  the  sepal  and 
of  the  petal.  Note  the  little  scale  at  the  base  of  the  petal,  inside. 

Strip  off  all  the  parts  from  a  flower  which  has  lost  its  petals, 
until  nothing  is  left  but  a  slender  conical  object  a  little  more  than 
an  eighth  of  an  inch  in  length.  This  is  the  receptacle  or  summit  of 
the  peduncle. 

In  a  fully  opened  flower,  note  the  numerous  yellow-tipped  stamens, 
each  consisting  of  a  short  stalk,  the  filament,  and  an  enlarged  yellow 
knob  at  the  end,  the  anther.  Note  the  division  of  the  anther  into 
two  portions,  which  appear  from  the  outside  as  parallel  ridges,  but 
which  are  really  closed  tubes,  the  anther-cells. 

Observe  in  the  interior  of  the  flower  the  somewhat  globular  mass 
(in  a  young  flower  almost  covered  by  the  stamens).  This  is  a  group 
of  pistils.  Study  one  of  these  groups  in  a  flower  from  which  the 
stamens  have  mostly  fallen  off,  and  make  an  enlarged  sketch  of  the 
head  of  pistils.  Remove  some  of  the  pistils  from  a  mature  head, 
and  sketch  a  single  one  as  seen  with  the  magnifying  glass.  Label 
the  little  knob  or  beak  at  the  upper  end  of  the  pistil  stigma,  and  the 
main  body  of  the  pistil  the  ovary.  Make  a  section  of  one  of  the 
pistils,  parallel  to  the  flattened  surfaces,  like  that  shown  in  Fig,  150, 
and  note  the  partially  matured  seed  within. 


CHAPTER   XV 


PLAN  AND   STRUCTURE   OF   THE   FLOWER  AND   ITS 
ORGANS 

208.  Parts  or  Organs  of  the  Flower.  —  Most  showy 
flowers  consist,  like  those  studied  in  the  preceding  chap- 
ter, of  four  circles  or  sets  of  organs,  the  sepals,  petals, 
stamens,  and  pistils.  The  sepals,  taken  together,  consti- 
tute the  calyx;  the  petals,  taken  together,  constitute  the 
corolla  (Fig.  138).1  Some- 
times it  is  convenient  to  have 
a  word  to  comprise  both  calyx 
and  corolla ;  for  this  the  term 
perianth  is  used.  A  flower 
which  contains  all  four  of 
these  sets  is  said  to  be  com- 
plete. Since  the  work  of  the 
flower  is  to  produce  seed,  and 
seed-forming  is  due  to  the 
cooperation  of  stamens  and 
pistils,  or,  as  they  are,  often 
called  from  their  relation  to  the  reproductive  organs  of 
spore-plants,  micro sporophylls  and  macrosporophylls  (see 
Sect.  374),  these  are  known  as  the  essential  organs 
(Fig.  138).  The  simplest  possible  pistil  is  a  dwarfed  and 

1  The  flower  of  the  waterleaf  Hydrophyllum  canadense,  modified  by  the 
omission  of  the  hairs  on  the  stamens,  is  here  given  because  it  shows  so  plainly 
the  relation  of  the  parts. 

197 


FIG.  138.  — The  Parts  of  the  Flower. 

cat,  calyx  ;  cor,  corolla ;  st, 

stamens;  p,  pistil. 


198 


FOUNDATIONS   OF   BOTANY 


greatly  modified  leaf  (Sect.  222),  adapted  into  a  seed- 
bearing  organ.  Such  a  pistil  may  be  one-seeded,  as  in 
Fig.  166,  or  several-seeded,  as  in  the  diagrammatic  one 
(Fig.  150) ;  it  is  called  a  carpel.  The  calyx  and  corolla  are 
also  known  as  the  floral  envelopes.  Flowers  which  have 
the  essential  organs  are  called  perfect  flowers.  They  may, 
therefore,  be  perfect  without  being  complete.  Incomplete 
flowers  with  only  one  row  of  parts  in  the 
perianth  are  said  to  be  apetalous  (Fig.  139). 
209.  Regular  and  Symmetrical  Flowers. 
—  A  flower  is  regular  if  all  the  parts  of 
the  same  set  or  circle  are  alike  in  size  and 
shape,  as  in  the  stonecrop  (Fig.  140).  Such 
flowers  as  that  of  the  violet,  the  monkshood, 
FIG.  139.  —  Apetai-  and  the  sweet  pea  (Fig.  141)  are  irregular. 

ous  Flower  of       ^  .          n 

(European)  wild    Symmetrical  flowers  are  those  whose  calyx, 

corolla,    circle    of    stamens,    and    set    of 

carpels  consist  each  of  the  same  number  of  parts,  or  in 

which   the   number  in  every  case    is   a  multiple   of  the 

smallest   number  found   in   any  set.     The    stonecrop  is 


I  II 

FIG.  140.  —  Flower  of  Stonecrop. 
I,  entire  flower  (magnified) ;  II,  vertical  section  (magnified). 

symmetrical,  since  it  has  five  sepals,  five  petals,  ten  sta- 
mens, and  five  carpels.     Roses,  mallows,  and  mignonette 


STRUCTURE   OF  THE  FLOWER  AND  ITS  ORGANS     199 


are  familiar  examples  of  flowers  which  are  unsymmet- 
rical  because  they  have  a  large,  indefinite  number  of 
stamens  ;  the  portulaca  is  unsymmetrical,  since  it  has  two 
divisions  of  the  calyx,  five  or  six  petals,  and  seven  to 
twenty  stamens. 

210.  The  Receptacle.  —  The  parts  of  the  flower  are 
borne  on  an  expansion  of  the  peduncle,  called  the  recep- 
tacle. Usually,  as  in  the  flower  of  the  grape  (Fig.  250), 
this  is  only  a  slight  enlargement  of  the  peduncle,  but  in 


FIG.  141.  —  Irregular  Corolla  of 
Sweet  Pea. 

I  A,  side  view  ;  B,  front  view  ;  s,  stand- 

A  ard  ;  w  w,  wings  ;  k,  keel. 


the  lotus  and  the  magnolia  the  receptacle  is  of  great  size, 
particularly  after  the  petals  have  fallen  and  the  seed  has 
ripened.  The  receptacle  of  the  rose  (Fig.  142)  is  hollow, 
and  the  pistils  arise  from  its  interior  surface. 

211.  Imperfect  or  Separated  Flowers.  -  -  The  stamens 
and  pistils  may  be  produced  in  separate  flowers,  which 
are,  of  course,  imperfect.  This  term  does  not  imply  that 
such  flowers  do  their  work  any  less  perfectly  than  others, 
but  only  that  they  have  not  both  kinds  of  essential  organs. 
In  the  very  simple  imperfect  flowers  of  the  willow  (Fig. 
143)  each  flower  of  the  catkin  (Fig.  131)  consists  merely 


200  FOUNDATIONS   OF   BOTANY 

of  a  pistil  or  a  group  of  (usually  two)  stamens,  springing 
from  the  axil  of  a  small  bract. 

Staminate  and  pistillate  flowers  may  be  borne  on  differ- 
ent plants,  as  they  are  in  the  willow,  or  they  may  be 
borne  on  the  same  plant,  as  in  the  hickory  and  the  hazel, 
among  trees,  or  in  the  castor-oil  plant,  Indian  corn,  and 
the  begonias.  When  staminate  and  pistillate  flowers  are 
borne  on  separate  plants,  such  a  plant  is  said  to  be 
dioecious,  that  is,  of  two  households ;  when  both  kinds  of 
flower  appear  on  the  same  individual,  the  plant  is  said 
to  be  monoecious,  that  is,  of  one  household. 

212,  Study  of  Imperfect  Flowers.  —  Examine,  draw,  and  describe 
the  imperfect  flowers  of  some  of  the  following  dioecious  plants  and 
one  of  the  monoecious  plants  : l 

f  early  meadow  rue. 

Dioecious  plants ^  willow. 

!  poplar. 

f  walnut,  oak,  chestnut. 

Monoecious  plants <  hickory,  alder,  beech. 

I  birch,  hazel,  begonia. 

213.  Union   of   Similar   Parts  of   the   Perianth. — The 
sepals  may  appear  to  join  or  cohere  to  form  a  calyx  which 
is  more  or  less  entirely  united  into  one  piece,  as  in  Figs. 
139  and  148.     In  this  case  the  calyx  is  said  to  be  gamo- 
sepalous,  that  is,  of  wedded  sepals.     In  the  same  way  the 
corolla  is  frequently  gamopetalous,  as  in  Figs.  144-148. 
Frequently  the  border  or  limb  of  the  calyx  or  corolla  is 
more  or  less  cut  or  lobed.     In  this  case   the  projecting 

1  For  figures  or  descriptions  of  these  or  allied  flowers  consult  Gray's 
Manual  of  Botany,  Emerson's  Trees  and  Shrubs  of  Massachusetts,  NewhalPs 
Trees  of  the  Northern  United  States,  or  Le  Maout  and  Decaisne's  Traite 
General  de  Botanique. 


STRUCTURE  OF  THE  FLOWER  AND  ITS  ORGANS    201 


FIG.  142. 


portions   of  the  limb   are   known  as  divisions,  teeth,   or 
lobes.1    Special  names  of  great  use  in  accurately  describing 
plants  are  given  to  a  large  number  of  forms  of  the  gamo- 
petalous    corolla.      Only    a    few    of   these 
names  are  here  given,  in  connection  with 
the  figures. 

When  the  parts  of  either  circle  of  the 
perianth  are  wholly  unconnected  with  each 
other,  that  is,  polysepalous  or  polypetalous, 
such  parts  are  said  to  be  distinct. 

214.  Parts  of  the  Stamen  and  the  Pistil. 
—  The  stamen  usually  consists  of  a  hollow 
portion,  the  anther  (Fig.  149,  a),  borne  on  a 
ARose,Longitudi-  stalk  called  the  filament  (Fig.  149, /),  which 
is  often  lacking.  Inside  the  anther  is  a  pow- 
dery or  pasty  substance  called  pollen  or  microspores  (Sect. 
374).  The  pistil  usually  consists  of  a  small  chamber,  the 
ovary,  which  contains  the  ovules,  macrospores  (Sect.  374), 
or  rudimentary  seeds,  a  slen- 
der portion  or  stalk,  called  the 
style,  and  at  the  top  of  this  a 
ridge,  knob,  or  point  called 
the  stigma.  These  parts  are 
all  shown  in  Fig.  150.  In 
many  pistils  the  stigma  is 
borne  directly  on  the  ovary. 
215.  Union  of  Stamens  with 
Each  Other. — Stamens  may 

be    wholly   Unconnected    With  A,  staminate  flower  ;  B,  pistillate  flower. 

1  It  would  not  be  safe  to  assume  that  the  gamosepalous  calyx  or  the  gamo- 
petalous  corolla  is  really  formed  by  the  union  of  separate  portions,  but  it  is 
very  convenient  to  speak  of  it  as  if  it  were. 


FIG.  143.  — Flowers  of  Willow. 
(Magnified.) 


202 


FOUNDATIONS   OF   BOTANY 


each  other  or  distinct,  or  they  may  cohere  by  their  fila- 
ments into  a  single  group,  when  they  are  said  to  be 
monadelphous,  of  one  brotherhood  (Fig. 
151),  into  two  groups  (diadelphous)  (Fig. 
152),  or  into  many  groups.  In  some 
flowers  the  stamens  are  held  together  in 
a  ring  by  their  coherent  anthers  (Fig. 
153). 

216.  Union  of  Pistils.  —  The  pistils 
may  be  entirely  separate  from  each 
other,  distinct  and  simple,  as  they  are 

FIG.  144. -Bell-Shaped      .  _  t" 

corolla  of  Beii-Fiower    in  the  buttercup  and  the  stonecrop,  or 
(Campanula).  several  may  join  to  form  one  compound 

pistil  of  more  or  less  united  carpels.  In  the  latter  case 
the  union  generally  affects  the  ovaries,  but  often  leaves 
the  styles  separate,  or  it  may  result 
in  joining  ovaries  and  styles,  but 
leave  the  stigmas  separate  or  at  any 
rate  lobed,  so  as  to  show  of  how 
many  separate  carpels  the  compound 
pistil  is  made  up.  Even  when  there 
is  no  external  sign  to  show  the 
compound  nature  of 
the  pistil,  it  can  usu- 
ally be  recognized 
from  the  study  of 
a  cross-section  of  the 


FIG.  145.  —  Salver-Shaped 
Corolla  of  Jasmine. 
(Magnified.) 


FIG.  146. 

Wheel-Shaped  Corolla 
of  Potato. 


ovary. 

217.    Cells  of  the 
Ovary ;   Placentas.  —  Compound    ovaries    are    very    com- 
monly several-celled,  that  is,  they  consist  of  a  number  of 


STRUCTURE  OF  THE  FLOWER  AND   ITS  ORGANS    203 


separate  cells1  or  chambers,  more  scientifically  known 
as  locules.  Fig.  154,  B,  shows  a  three-celled  ovary 
seen  in  cross-section.  The  ovules  are  not  borne  indis- 
criminately by  any  part  of  the  lining  of  the  ovary.  In 
one-celled  pistils  they  frequently  grow  in  a  line  running 
along  one  side  of  the  ovary,  as  in  the  pea  pod  (Fig.  271). 
The  ovule-bearing  line  is  called  a  placenta;  in  compound 
pistils  there  are  commonly  as  many  placentas  as  there  are 


FIG.  147.  — Tubu- 
lar Corolla,  from 
Head  of  Bache- 
lor's Button. 


FIG.  148.  —  Labi- 
ate or  Ringent 
Corolla  of  Dead 
Nettle. 


FIG.  149.  —  Parts  of  a 

Stamen. 

A,  front ;  B,  back  ;  a,  an- 
ther ;  c,  connective; 
/,  filament. 


FIG.  150.  —  Parts 
of  the  Pistil. 

ov,  ovary. 
sty,  style. 
stig,  stigma. 


separate  pistils  joined  to  make  the  compound  one.  Pla- 
centas on  the  wall  of  the  ovary,  like  those  in  Fig.  154,  A, 
are  called  parietal  placentas  ;  those  which  occur  as  at  B, 
in  the  same  figure,  are  said  to  be  central,  and  those  which, 
like  the  form  represented  in  0  of  the  same  figure,  consist 
of  a  column  rising  from  the  bottom  of  the  ovary  are 
called  free  central  placentas. 

1  Notice  that  the  word  cell  is  here  used  in  an  entirely  different  sense  ^rom 
that  in  which  it  has  been  employed  in  the  earlier  chapters  of  this  book.  As 
applied  to  the  ovary,  it  means  a  chamber  or  compartment. 


204 


FOUNDATIONS   OF  BOTANY 


218.  Union  of  Separate  Circles.  —  The  members  of  one 
of  the  circles  of  floral  organs  may  join  those  of  another 
circle,   thus   becoming    adnate,   adherent,   or   consolidated. 

In  Fig.  139  the  calyx  tube  is  adnate  to  the 
ovary.  In  this  case  the  parts  of  the  flower  do 
not  all  appear  to  spring  from  the  receptacle. 
Fig.  155  illustrates  three  common  cases  as 
regards  insertion  of  the  parts  of  the  flower. 
In  I  they  are  all  inserted  on  the  receptacle, 
and  the  corolla  and  stamens  are  said  to  be 
hypogynous,  that  is,  beneath  the  pistil.  In  II 
the  petals  and  the  stamens  appear  as  if  they 
had  grown  fast  to  the  calyx  for  some  distance, 
so  that  they  surround  the  pistil,  and  they  are 

therefore    said    to    be  perigynous,   that   is, 

around  the  pistil.     In  III  all  the  parts  are 

free  or  unconsolidated,   except  the  petals 

arid  stamens  ;  the  stamens  may  be  described 

as  epipetalous,  that  is,  growing  on  the  petals. 
Sometimes  some  or  all 
of  the  other  parts  stand 
upon  the  ovary,  and  such 

FIG.  152.  -Diadeiphous    parts  are  said  to  be  epig- 

Stamens  of  Sweet  Pea.       ynou^    that     IS,     On     the 

ovary,  like  the  petals  and  stamens  of  the 
white  water-lily  (Fig.  156). 

219.  Floral   Diagrams.  —  Sections    (real 
or  imaginary)   through   the   flower  length- 
wise, like  those  of  Fig.  155,  help  greatly 

in  giving  an  accurate  idea  of  the  relative  «,™»ted  anthers;/, 

filaments,  bearded 

position  of  the  floral   organs.      Still    more     on  the  sides. 


<• 


FIG.  153.  — Stamens 
of  a  Thistle,  with 
Anthers  united 
into  a  King. 


STRUCTURE  OF  THE  FLOWER  AND  ITS  ORGANS    205 


important  in  this  way  are  cross-sections,  which  may  be 
recorded  in  diagrams  like  those  of  Fig.  157. l  In  con- 
structing such  diagrams  it 
will  often  be  necessary  to 
suppose  some  of  the  parts 
of  the  flower  to  be  raised 
or  lowered  from  their  true 
position,  so  as  to  bring 
them  into  such  relations 
that  all  could  be  cut  by  a 
single  section.  This  would,  for  instance,  be  necessary 
in  making  a  diagram  for  the  cross-section  of  the  flower 


A~  ~B~  C 

FIG.  154.  —  Principal  Types  of  Placenta. 
A,  parietal  placenta  ;  B,  central  placenta ; 
C,  free  central  placenta  ;  A  and  B,  trans- 
verse sections  ;  C,  longitudinal  section. 


I  II  III 

FIG.  155.  — Insertion  of  the 

Floral  Organs. 

I,  Hypogynous,  all  the  other  parts  on 
the  receptacle,  beneath  the  pistil ; 
II,  Perigynous,  petals  and  stamens 
apparently  growing  out  of  the  calyx, 
around  the  pistil ;  III,  corolla 
hypogynous,  stamens  epipetalous. 


FIG.  156.  — White  Water-Lily.  The 
inner  petals  and  the  stamens  grow- 
ing from  the  ovary. 


of  the   white  water-lily,  of  which  a  partial  view  of  one 
side  is  shown  in  Fig.  156.2 

1  For  floral  diagrams  see  Le  Maout  and  Decaisne's   Traite  General  de 
Botanique,  or  Eichler's  Bliithendiagramme. 

2  It  is  best  to  begin  practice  on  floral  diagrams  with  flowers  so  firm  and 
large  that  actual  sections  of  them  may  be  cut  with  ease  and  the  relations  of 
the  parts  in  the  section  readily  made  out.    The  tulip  is  admirably  adapted 
for  this  purpose. 


206 


FOUNDATIONS   OF   BOTANY 


Construct  diagrams  of  the  longitudinal  section  and  the 
transverse  section  of  several  large  flowers,  following  the 
method   indicated   in    Figs.    155    and    157,    but   making 
•  the   longitudinal    section    show 

the  interior  of   the  ovary.1     It 
is  found  convenient  to   distin- 


I  II  III 

FIG.  157.  —  Diagram  of  Cross-Sections  of  Flowers. 

I,  columbine  ;  II,  heath  family  ;  III,  iris  family.  In  each  diagram  the  dot  along- 
side the  main  portion  indicates  a  cross-section  of  the  stem  of  the  plant.  In 
II  every  other  stamen  is  more  lightly  shaded,  because  some  plants  of  the 
heath  family  have  five  and  some  ten  stamens. 

guish  the  sepals  from  the  petals  by  representing  the 
former  with  midribs.  The  diagrammatic  symbol  for  a 
stamen  stands  for  a  cross-section  of  the  anther,  and  that 
for  the  pistil  is  a  section  of  the  ovary.  If  any  part  is 
lacking  in  the  flower  (as  in  the  case  of  flowers  which 
have  some  antherless  filaments)  the  missing  or  abortive 
organ  may  be  indicated  by  a  dot.  In  the  diagram  of  the 
Iris  Family  (Fig.  157,  III)  the  three  dots  inside  the  flower 
indicate  the  position  of  a  second  circle  of  stamens,  found 
in  most  flowers  of  monocotyledons  but  not  found  in  this 
family. 

1  Among  the  many  excellent  early  flowers  for  this  purpose  may  be  men- 
tioned trillium,  bloodroot,  dogtooth  violet,  marsh  marigold,  buttercup,  tulip 
tree,  horse-chestnut,  Jeffersonia,  May-apple,  cherry,  apple,  crocus,  tulip, 
daffodil,  primrose,  wild  ginger,  cranesbill,  locust,  bluebell. 


"  STRUCTURE  OF  THE  FLOWER  AND  ITS  ORGANS     207 
220.    Review  Summary  of  Chapter  XV.1 


Kinds  of  flowers  as  regards  number  of  circles  or       I   2. 
•jets  of  organs  present j  3. 

U 
Kinc's  as  regards  numerical  plan 

Kinds  as  regards  similarity  of  parts  of  the  same        f  1. 
circle I  2. 


Parts  of  a  stamen 


Parts  of  a  pistil 


Stamens  as  regards  union  with  each  other 

Pistils  as  regards  union  with  each  other  . 

Degree  of  union  of  separate  circles      .     . 

1  Illustrate  by  sketches. 


CHAPTER    XVI 


TRUE    NATURE    OF   FLORAL    ORGANS;    DETAILS    OF 
THEIR    STRUCTURE;  FERTILIZATION 

221,  The  Flower  a  Shortened  and  greatly  Modified 
Branch.  —  In  Chapter  VIII,  the  leaf-bud  was  explained 
as  being  an  undeveloped  branch,  which  in  its  growth 
would  develop  into  a  real  branch  (or  a  prolongation  of 
the  main  stem).  Now,  since  flower-buds  appear  regularly 


FIG.  158.  —  Transition  from  Bracts  to  Sepals  in  a  Cactus  Flower. 

either  in  the  axils  of  leaves  or  as  terminal  buds,  there  is 
reason  to  regard  them  as  of  similar  nature  to  leaf-buds. 
This  would  imply  that  the  receptacle  corresponds  to  the 
axis  of  the  bud  shown  in  Fig.  86,  and  that  the  parts  of 
the  flower  correspond  to  leaves.  There  is  plenty  of  evi- 
dence that  this  is  really  true.  Sepals  frequently  look 
very  much  like  leaves,  and  in  many  cacti  the  bracts 

208 


TRUE  NATURE  OF  FLORAL  ORGANS 


209 


about  the  flower  are  so  sepal-like  that  it  is  impossible  to 
tell  where  the  bracts  end  and  the  sepals  begin  (Fig.  158). 
The  same  thing  is  true  of  sepals  and  petals  in  such  flowers 
as  the  white  water-lily.  In  this  flower  there  is  a  remark- 
able series  of  intermediate  steps,  ranging  all  the  way  from 
petals,  tipped  with  a  bit  of  anther,  through  stamens  with 
a  broad  petal-like  filament,  to  regular  stamens,  as  is  shown 
in  Fig.  159,  E,  F,  6r,  H.  The  same  thing  is  shown  in 


E 


FIG.  159.  —  Transitions  from  Petals  to  Stamens  in  White  Water-Lily. 
E,  F,  G,  H,  various  steps  between  petal  and  stamen. 

many  double  roses.  In  completely  double  flowers  all  the 
essential  organs  are  transformed  by  cultivation  into  petals. 
In  the  flowers  of  the  cultivated  double  cherry  the  pistils 
occasionally  take  the  form  of  small  leaves,  and  some  roses 
turn  wholly  into  green  leaves. 

Summing  up,  then,  we  know  that  flowers  are  altered 
and  shortened  branches  :  (1)  because  flower-buds  have  as 
regards  position,  the  same  kind  of  origin  as  leaf-buds ; 
(2)  because  all  the  intermediate  steps  are  found  between 
bracts,  on  the  one  hand,  and  stamens,  on  the  other ;  (3) 


210  FOUNDATIONS  OF  BOTANY 

because  the  essential  organs  are  found  to  be  replaced  by 
petals  or  even  by  green  leaves. 

The  fact  that  leaves  should  be  so  greatly  modified  as 
they  are  in  flowers  and  given  work  to  do  wholly  different 
from  that  of  the  other  kinds  of  leaves  so  far  studied  need 
not  strike  one  as  exceptional.  In  many  of  the  most  highly 
developed  plants  below  the  seed-plants,  organs  correspond- 
ing to  flowers  are  found,  and  these  consist  of  modified 
leaves,  set  apart  for  the  work  of  reproducing  (Sect.  367). 

222.  Mode  of  Formation  of  Stamens  and  Pistils  from 
Leaves.  —  It  is  hardly  possible  to  state,  until  after  Chap- 
ter XXIII  has  been  studied,  how  stamens  stand  related 
to  leaves.1 

The  simple  pistil  or  carpel  is  supposed  to  be  made  on 
the  plan  of  a  leaf  folded  along  the  midrib  until  its  margins 
touch,  like  the  cherry  leaf  in  Fig.  87.  But  the  student 
must  not  understand  by  this  statement  that  the  little 
pistil  leaf  grows  at  first  like  an  ordinary  leaf  and  finally 
becomes  folded  in.  The  united  leaf-margins  near  the  tip 
would  form  the  stigma,  and  the  placenta  would  correspond 
to  the  same  margins,  rolled  slightly  inwards,  extending 
along  the  inside  of  the  inflated  leaf-pouch.  Place  several 
such  folded  leaves  upright  about  a  common  center,  and 
their  cross-section  would  be  much  like  that  of  B  in  Fig. 
154.  Evidence  that  carpels  are  really  formed  in  this  way 
may  be  gained  from  the  study  of  such  fruits  as  that  of 
the  monkshood  (Fig.  168),  in  which  the  ripe  carpels  may 
be  seen  to  unfold  into  a  shape  much  more  leaf -like  than 
that  which  they  had  while  the  pistil  was  maturing.  What 

1  "The  anther  answers  exactly  to  the  spore-cases  of  the  ferns  and  their 
allies,  while  the  filament  is  a  small  specialized  leaf  to  support  it."  For  a 
fuller  statement,  see  Potter  and  Warming's  Systematic  Botany,  pp.  236,  237. 


TRUE  NATURE  OF  FLORAL  ORGANS 


211 


really  occurs  is  this:  the  flower-bud,  as  soon  as  it  has 
developed  far  enough  to  show  the  first  rudiments  of  the 
essential  organs,  contains  them  in  the  form  of  minute 
knobs.  These  are  developed  from  the  tissues  of  the  plant 
in  the  same  manner  as  are  the  knobs  in  a  leaf-bud,  which 
afterwards  become  leaves  (Fig.  87,  II)  ;  but  as  growth 
and  development  progress 
in  the  flower-bud,  its  con- 
tents soon  show  themselves 
to  be  stamens  and  pistils  (if 
the  flower  is  a  perfect  one). 

223.  The  Anther  and  its 
Contents. — Some  of  the 
shapes  of  the  anthers  may 
be  learned  from  Figs.  149 
and  160.1  The  shape  of  the  FlG- 16°— Modes  of  *****&* Pollen- 
anther  and  the  way  in  which 
it  opens  depend  largely  upon 
the  way  in  which  the  pollen 
is  to.be  discharged  and  how  it  is  carried  from  flower  to 
flower.  The  commonest  method  is  to  have  the  anther- 
cells  split  lengthwise,  as  in  Fig.  160,  I.  A  few  anthers 
open  by  trap-doors  like  valves,  as  in  II,  and  a  larger 
number  by  little  holes  at  the  top,  as  in  III. 

The  pollen  in  many  plants  with  inconspicuous  flowers, 
as  the  evergreen  cone-bearing  trees,  the  grasses,  rushes, 
and  sedges,  is  a  fine,  dry  powder.  In  plants  with  showy 
flowers  it  is  often  somewhat  sticky  or  pasty.  The  forms 
of  pollen  grains  are  extremely  various.  Fig.  161  will 
serve  to  furnish  examples  of  some  of  the  shapes  which 


(amaryllis); 

berry);  III,  by  a  pore  at  the  top  of  each 

anther-lobe  (nightshade). 


1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  II,  pp.  86-95, 


212  FOUNDATIONS   OF   BOTANY 

the  grains  assume  ;  c  in  the  latter  figure  is  perhaps  as 
common  a  form  as  any.  Each  pollen  grain  consists  mainly 
of  a  single  cell,  and  is  covered  by  a  moderately  thick  outer 
wall  and  a  thin  inner  one.  Its  contents  are  thickish 
protoplasm,  full  of  little  opaque  particles  and  usually 
containing  grains  of  starch  and  little  drops  of  oil.  The 
knobs  on  the  outer  coat,  as  shown  in  Fig.  161  5,  mark 


a  b  c  d  e 

FIG.  161.  —  Pollen  Grains.     (Very  greatly  magnified.) 
a,  pumpkin  ;  b,  enchanter's  nightshade  ;  c,  Albuca  ;  d,  pink  ;  e,  hibiscus. 

the  spots  at  which  the  inner  coat  of  the  grain  is  finally 
to  burst  through  the  outer  one,  pushing  its  way  out  in 
the  form  of  a  slender,  thin-walled  tube.1 

224,  The  Formation  of  Pollen  Tubes.  —  This  can  be 
studied  in  pollen  grains  which  have  lodged  on  the  stigma 
and  there  been  subjected  to  the  action  of  its  moist  surface. 
It  is,  however,  easier  to  cause  the  artificial  production  of 
the  tubes. 

EXPERIMENT   XXXVIII 

Production  of  Pollen  Tubes.  —  Place  a  few  drops  of  suitably  diluted 
syrup  with  some  fresh  pollen  in  a  concave  cell  ground  in  a  micro- 
scope slide ;  cover  with  thin  glass  circle  ;  place  under  a  bell-glass, 
with  a  wet  cloth  or  sponge,  to  prevent  evaporation  of  the  syrup,  and 
set  aside  in  a  warm  place,  or  merely  put  some  pollen  in  syrup  in  a 

i  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  II,  pp.  95-104. 


FERTILIZATION 


213 


watch  crystal  under  the  bell-glass.  Examine  from  time  to  time  to 
note  the  appearance  of  the  pollen  tubes.  Try  several  kinds  of 
pollen  if  possible,  using  syrups  of  various  strengths.  The  follow- 
ing kinds  of  pollen  form  tubes  readily  in  syrups  of  the  strengths 
indicated. 

Tulip  .         ..       .         -.         .         .         .         1  to  3  per  cent. 

Narcissus     .         .         «         ..        .  :  '      3  to  5       " 

Cytisus  canariensis  (called  Genista  by  florists)  15       " 

Chinese  primrose 10       " 

Sweet  pea1  ......     10  to  15       " 

Tropa3olum1        .         ^        .         ..  .  15       " 

225.  Microscopical  Structure  of  the  Stigma  and  Style.  - 
Under  a  moderate  power  of  the  microscope  the  stigma  is 
seen  to  consist  of  cells  set  irregularly  over  the  surface, 
and  secreting  a  moist  liquid  to 
which  the  pollen  grains  adhere  (Fig. 
162).  Beneath  these  superficial  cells 
and  running  down  through  the  style 
(if  there  is  one)  to  the  ovary  is 
spongy  parenchyma.  In  some  pistils 
the  pollen  tube  proceeds  through 
the  cell  walls,  which  it  softens  by 
means  of  a  substance  which  it  exudes 
for  that  purpose.  In  other  cases 
(Fig.  163)  there  is  a  canal  or  passage, 
along  which  the  pollen  tube  travels 
on  its  way  to  the  ovule. 


FIG.  162.  — Stigma  of  Thorn- 
Apple  (Datura)  with  Pollen. 
(Magnified.) 


1  The  sweet-pea  pollen  and  that  of  Tropaeolum  are  easier  to  manage  than 
any  other  kinds  of  which  the  author  has  personal  knowledge.  If  a  concaved 
slide  is  nqt  available,  the  cover-glass  may  be  propped  up  on  bits  of  the  thin- 
nest broken  cover-glasses.  From  presence  of  air  or  some  other  reason,  the 
formation  of  pollen  tubes  often  proceeds  most  rapidly  just  inside  the  margin 
of  the  cover-glass. 


214 


FOUNDATIONS   OF   BOTANY 


226.  Fertilization.  —  By  fertilization  in  seed-plants  the 
botanist  means  the  union  of  a  generative  cell  from  a  pol- 
p  len  grain  with  that  of  an  egg-cell 
at  the  apex  of  the  embryo  sac 
(Fig.  165).  This  process  gives 
rise  to  a  cell  which  contains 
material  derived  from  the  pollen 
and  from  the  egg-cell.  In  a 
great  many  plants  the  pollen, 
in  order  to  accomplish  the  most 
successful  fertilization,  must 
come  from  another  plant  of  the 
same  kind,  not  from  the  indi- 
vidual which  bears  the  ovules 
that  are  being  fertilized. 

Pollen  tubes  begin  to  form 
soon  after  pollen  grains  lodge 
on  the  stigma.  The  time  re- 

FIG.  163.  —  Pollen  Grains  producing  •        -i    <•         ,  i  i 

Tubes,  on  stigma  of  a  Lily.  (Much  quired  for  the  process  to  begin 
magnified.)  varies     in    different    kinds    of 

q,  pollen  grains  ;  t,  pollen  tubes  ;  p,        ,  ... 

of  stigma  ;c>  canal  or  pas-  plants,  requiring  in  many  cases 
twenty-four  hours  or  more.  The 
length  of  time  needed  for  the 
pollen  tube  to  make  its  way 
through  the  style  to  the  ovary 
depends  upon  the  length  of  the 

FIG.  164. -Pollen  Grain  of  Snow-    gtyle    and   other  conditions.       Jn 
flake  (Leucoium)  producing  a  Pol-        » 
len  Tube  with  Two  Naked  Genera-    the     CrOCUS,     which    has     a    Style 

several  inches  long,  the  descent 
takes  from  one  to  three  days. 

Finally  the  tube  penetrates  the  opening  at  the  apex  of 


sage  running  toward  ovary. 


FERTILIZATION 


215 


the  ovule  ra,  in  Fig.  165,  reaches  one  of  the  cells  shown 
at  e,  and  transfers  a  generative  cell  into  this  egg-cell.  The 
latter  is  thus  enabled  to 
divide  and  grow  rapidly 
into  an  embryo.  This 
the  cell  does  by  forming 
cell-walls  and  then  in- 
creasing by  continued 
subdivision,  in  much  the 
same  way  in  which  the 
cells  at  the  growing  point 
near  the  tip  of  the  root,  *• 
or  those  of  the  cambium 
layer,  subdivide.1 

227.  Nature  of  the 
Fertilizing  Process. - 
The  necessary  feature  of 
the  process  of  fertiliza- 
tion is  the  union  of  the 
essential  contents  of  two 
cells  to  form  a  new  one, 
from  which  the  future 
plant  is  to  spring.  This 
kind  of  union  is  found 
to  occur  in  many  cryp- 
togams  (Chapters 
XX- XXII),  .  resulting 
in  the  production  of 
a  spore  capable  of  grow- 
ing into  a  complete  plant  like  that  which  produced  it. 

1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  II,  pp.  401-420. 


FIG.  165.  —  Diagrammatic  Representation  of 
Fertilization  of  an  Ovule. 

i,  inner  coating  of  ovule  ;  o,  outer  coating  of 
ovule;  p,  pollen  tube,  proceeding  from  one 
of  the  pollen  grains  on  the  stigma  ;  c,  the 
place  where  the  two  coats  of  the  ovule 
blend.  (The  kind  of  ovule  here  shown  is 
inverted,  its  opening  m  being  at  the  bottom, 
and  the  stalk  /  adhering  along  one  side  of 
the  ovule.)  a  to  e,  embryo  sac,  full  of  pro- 
toplasm ;  a,  so-called  antipodal  cells  of  em- 
bryo sac  ;  n,  central  nucleus  of  the  embryo 
sac ;  e,  nucleated  cells,  one  of  which,  the 
egg-cell,  receives  the  essential  contents  of 
the  pollen  tube ;  /,  funiculus  or  stalk  of 
ovule ;  m,  opening  into  the  ovule. 


216  FOUNDATIONS   OF   BOTANY  ' 

228,  Number  of  Pollen  Grains  to  Each  Ovule.  —  Only 
one  pollen  tube  is  necessary  to  fertilize  each  ovule,  but 
so  many  pollen  grains  are  lost  that  plants  produce  many 
more  of  them  than  of  ovules.  The  ratio,  however,  varies 
greatly.  In  the  night-blooming  cereus  there  are  about 
250,000  pollen  grains  for  30,000  ovules,  or  rather  more 
than  8  to  1,  while  in  the  common  garden  wistaria  there 
are  about  7000  pollen  grains  to  every  ovule,  and  in  Indian 
corn,  the  cone-bearing  evergreens,  and  a  multitude  of  other 
plants,  many  times  more  than  7000  to  1.  These  differences 
depend  upon  the  mode  in  which  the  pollen  is  carried  from 
the  stamens  to  the  pistil. 


CHAPTER   XVII 
THE    STUDY    OF    TYPICAL   FRUITS 

229,  A  Berry,  the  Tomato.1  —  Study  the   external  form  of  the 
tomato,  and  make  a  sketch  of  it  showing  the  persistent  calyx  and 
peduncle. 

Cut  a  cross-section  at  about  the  middle  of  the  tomato.  Note  the 
thickness  of  the  epidermis  (peel  off  a  strip)  and  of  the  wall  of  the 
ovary.  Note  the  number,  size,  form,  and  contents  of  the  cells  of 
the  ovary.  Observe  the  thickness  and  texture  of  the  partitions 
between  the  cells.  Sketch. 

Note  the  attachments  of  the  seeds  to  the  placentas  and  the  gelati- 
nous, slippery  coating  of  each  seed. 

The  tomato  is  a  typical  berry,  but  its  structure  presents  fewer 
points  of  interest  than  are  found  in  some  other  fruits  of  the  same 
general  character,  so  the  student  will  do  well  to  spend  a  little  more 
time  on  the  examination  of  such  fruits  as  the  orange  or  the  lemon. 

230.  A  Hesperidium,  the  Lemon.  —  Procure  a  large  lemon  which 
is  not  withered,  if  possible  one  which  still  shows  the  remains  of  the 
calyx  at  the  base  of  the  fruit. 

Note  the  color,  general  shape,  surface,  remains  of  the  calyx, 
knob  at  portion  formerly  occupied  by  the  stigma.  Sketch  the  fruit 
about  natural  size.  Examine  the  pitted  surface  of  the  rind  with 
the  magnifying  glass  and  sketch  it.  Kemove  the  bit  of  stem  and 
dried-up  calyx  from  the  base  of  the  fruit ;  observe,  above  the  calyx, 
the  knob  or  disk  on  which  the  pistil  stood.  Note  with  the  magni- 
fying glass  and  count  the  minute  whitish  raised  knobs  at  the  bottom 
of  the  saucer-shaped  depression  left  by  the  removal  of  the  disk. 
What  are  they  ? 

1  Fresh  tomatoes,  not  too  ripe,  are  to  be  used,  or  those  which  have  been  kept 
over  from  the  previous  summer  in  formalin  solution.  The  very  smallest 
varieties,  such  as  are  often  sold  for  preserving,  are  as  good  for  study  as  the 
larger  kinds. 

217 


218  FOUNDATIONS   OF   BOTANY 

Make  a  transverse  section  of  the  lemon,  not  more  than  a  fifth  of 
the  way  down  from  the  stigma  end  and  note  : 

(1)  The  thick  skin,  pale  yellow  near  the  outside,  white  within. 

(2)  The  more  or  less  wedge-shaped  divisions  containing  the  juicy 
pulp  of  the  fruit.     These  are  the  matured  cells  of  the  ovary  ;  count 
these. 

(3)  The  thin  partition  between  the  cells. 

(4)  The  central  column  or  axis  of  white  pithy  tissue. 

(5)  The   location    and   attachment  of  any   seeds   that   may  be 
encountered  in  the  section. 

Make  a  sketch  to  illustrate  these  points,  comparing  it  with 
Fig.  171. 

Study  the  section  with  the  magnifying  glass  and  note  the  little 
spherical  reservoirs  near  the  outer  part  of  the  skin,  which  contain  the 
oil  of  lemon  which  gives  to  lemon  peel  its  characteristic  smell  and 
taste.  Cut  with  the  razor  a  thin  slice  from  the  surface  of  a  lemon 
peel,  some  distance  below  the  section,  and  at  once  examine  the 
freshly  cut  surface  with  a  magnifying  glass  to  see  the  reservoirs, 
still  containing  oil,  which,  however,  soon  evaporates.  On  the  cut 
surface  of  the  pulp  (in  the  original  cross-section)  note  the  tubes  in 
which  the  juice  is  contained.  These  tubes  are  not  cells,  but  their 
walls  are  built  of  cells.  Cut  a  fresh  section  across  the  lemon,  about 
midway  of  its  length  and  sketch  it,  bringing  out  the  same  points 
which  were  shown  in  the  previous  one.  The  fact  that  the  number 
of  ovary  cells  in  the  fruit  corresponds  with  the  number  of  minute 
knobs  in  the  depression  at  its  base  is  due  to  the  fact  that  these 
knobs  mark  the  points  at  which  fibro-vascular  bundles  passed  from 
the  peduncle  into  the  cells  of  the  fruit,  carrying  the  sap  by  which 
the  growth  of  the  latter  was  maintained. 

Note  the  toughness  and  thickness  of  the  seed-coats.  Taste  the 
kernel  of  the  seed. 

Cut  a  very  thin  slice  from  the  surface  of  the  skin,  mount  in 
water,  and  examine  with  a  medium  power  of  the  microscope. 
Sketch  the  cellular  structure  shown  and  compare  it  with  the  sketch 
of  the  corky  layer  of  the  bark  of  the  potato  tuber. 

Of  what  use  to  the  fruit  is  a  corky  layer  in  the  skin?  (See  Sect. 
453  for  further  questions.) 


THE    STUDY   OF   TYPICAL   FRUITS  219 

231.  A  Legume,  the  Bean-Pod.1  —  Lay  the  pod  flat  on  the  table 
and  make  a  sketch  of  it,  about  natural  size.     Label  stigma,  style, 
ovary,  calyx,  peduncle. 

Make  a  longitudinal  section  of  the  pod,  at  right  angles  to  the 
plane  in  which  it  lay  as  first  sketched,  and  make  a  sketch  of  the 
section,  showing  the  partially  developed  seeds,  the  cavities  in  which 
they  lie,  and  the  solid  portion  of  the  pod  between  each  bean  and 
the  next. 

Split  another  pod,  so  as  to  leave  all  the  beans  lying  undisturbed 
on  one-half  of  it  and  sketch  that  half,  showing  the  beans  lying  in 
their  natural  position  and  the  funiculus  or  stalk  by  which  each  is 
attached  to  the  placenta ;  compare  Fig.  271. 

Make  a  cross-section  of  another  pod,  through  one  of  the  beans, 
sketch  the  section,  and  label  the  placenta  (formed  by  the  united 
edges  of  the  pistil  leaf)  and  the  midrib  of  the  pistil  leaf. 

Break  off  sections  of  the  pod  and  determine,  by  observing  where 
the  most  stringy  portions  are  found,  where  the  nbro-vascular  bundles 
are  most  numerous. 

Examine  some  ripe  pods  of  the  preceding  year,2  and  notice  where 
the  dehiscence,  or  splitting  open  of  the  pods,  occurs,  whether  down 
the  placental  edge,  ventral  suture,  the  other  edge,  dorsal  suture,  or 
both. 

232.  An  Akene,  the  Fruit  of  Dock.  —  Hold  in  the  forceps  a  ripe 
fruit  of  any  of  the  common  kinds  of  dock,3  and  examine  with  the 
magnifying  glass.    Note  the  three  dry,  veiny,  membranaceous  sepals 
by  which  the  fruit  is  enclosed.     On  the  outside  of  one  or  more  of 
the  sepals  is  found  a  tubercle  or  thickened  appendage  which  looks 
like  a  little  seed  or  grain.     Cut  off  the  tubercles  from  several  of  the 
fruits,  put  these,  with  some  uninjured  ones,  to  float   in  a  pan  of 
water,  and  watch  their  behavior  for  several  hours.     What  is  appar- 
ently the  use  of  the  tubercle  ? 

1  Any  species  of  bean  (Phaseolus)  will  answer  for  this  study.    Specimens 
in  the  condition  known  at  the  markets  as  "  shell-beans  "  would  be  best,  but 
these  are  not  obtainable  in  spring.     Ordinary  "  string-beans  "  will  do. 

2  Which  may  be  passed  round  for  that  purpose.    They  should  have  been 
saved  and  dried  the  preceding  autumn. 

8  Rumex  crispus,  R.  obtusifolius,  or  R.  verticillatus.  This  should  have 
been  gathered  and  dried  the  preceding  summer. 


220  FOUNDATIONS  OF  BOTANY 

Of  what  use  are  the  sepals,  after  drying  up  ?  Why  do  the  fruits 
cling  to  the  plant  long  after  ripening? 

Carefully  remove  the  sepals  and  examine  the  fruit  within  them. 
What  is  its  color,  size,  and  shape?  Make  a  sketch  of  it  as  seen  with 
the  magnifying  glass.  Note  the  three  tufted  stigmas,  attached  by 
slender  threads  to  the  apex  of  the  fruit.  What  does  their  tufted 
shape  indicate  ? 

What  evidence  is  there  that  this  seed-like  fruit  is  not  really  a 
seed? 

Make  a  cross-section  of  a  fruit  and  notice  whether  the  wall  of 
the  ovary  can  be  seen,  distinct  from  the  seed-coats.  Compare  the 
dock  fruit  in  this  respect  with  the  fruit  of  the  buttercup,  shown  in 
Fig.  166.  Such  a  fruit  as  either  of  these  is  called  an  akene. 


CHAPTER    XVIII 
THE    FRUIT1 

233,  What  constitutes  a  Fruit.  —  It  is  not  easy  to  make 
a  short  and  simple  definition  of  what  botanists  mean  by 
the  teim  fruit.     It  has  very  little  to  do  with  the  popular 
use  of  the  word.     Briefly  stated,  the    definition  may  be 
given  as  follows  :    The  fruit  consists  of  the  matured  ovary 
and  contents,  together  with  any  intimately  connected  parts. 
Botanically  speaking,  the  bur  of  beggar's  ticks  (Fig.  273), 
the  three-cornered  grain  of  buckwheat,  or  such  true  grains 
as  wheat  and  oats,  are  as  much  fruits  as  is  an  apple  or  a 
peach. 

The  style  or  stigma  sometimes  remains  as  an  important 
part  of  the  fruit  in  the  shape  of  a  hook,  as  in  the  common 
hooked  crowfoot ;  or  in  the  shape  of  a  plumed  appendage, 
as  in  the  virgin's  bower,  often  called  wild  hops.  The 
calyx  may  develop  hooks,  as  in  the  agrimony,  or  plumes, 
as  in  the  thistle,  the  dandelion,  lettuce,  and  many  other 
familiar  plants.  In  the  apple,  pear,  and  very  many  ber- 
ries, the  calyx  becomes  enlarged  and  pulpy,  often  consti- 
tuting the  main  bulk  of  the  mature  fruit.  The  receptacle 
not  infrequently,  as  in  the  apple,  forms  a  more  or  less 
important  part  of  the  fruit. 

234.  Indehiscent  and    Dehiscent    Fruits All   of   the 

fruits  considered  in  the  next  three  sections  are  indehiscent, 

1  See  Gray's  Structural  Botany,  Chapter  VII,  also  Kerner  and  Oliver's 
Natural  History  of  Plants,  Vol.  II,  pp.  427-438. 
•  221 


222 


FOUNDATIONS   OF   BOTANY 


FIG.  166.  —  Akenes  of  a  Buttercup. 

A,  head  of  akenes  ;  B,  section  of  a  single 

akene  (magnified) ;  a,  seed. 


that   is,    they   remain    closed    after   ripening.      Dehiscent 
fruits  when  ripe  open  in  order  to  discharge  their  seeds. 

The  three  classes  which  im- 
mediately follow  Sect.  237 
belong  to  this  division. 

235.  The  Akene.  —  The 
one-celled  and  one-seeded 
pistils  of  the  buttercup, 
strawberry,  and  many  other 
flowers,  ripen  into  a  little 
fruit  called  an  akene  (Fig. 
166).  Such  fruits,  from 
their  small  size,  their  dry 
consistency,  and  the  fact  that  they  never  open,  are  usually 
taken  for  seeds  by  those  who  are  not  botanists. 

In  the  group  of  plants  to  which  the  daisy,  the  sunflower, 
and  the  dandelion  belong,  the  akenes  consist  of  the  ovary 
and  the  adherent  calyx  tube.  The  limb  of  the  calyx  is 
borne  on  the  summit  of  many  akenes,  sometimes  in  the  form 
of  teeth,  sometimes  as  a  tuft 
of  hairs  or  bristles  (Fig.  267).  ^ 

236.  The   Grain.  —  Grains, 
such  as  corn,  wheat,  oats,  bar- 
ley, rice,  and  so  on,  have  the 
interior    of    the    ovary    com- 
pletely filled  by  the  seed,  and 
the  seed-coats  and  the  wall  of 
the  ovary  are  firmly  united,  as 
shown  in  Fig.  6. 

237.  The  Nut. — A  nut  (Fig.  167)    is   larger   than  an 
akene,  usually  has  a  harder  shell,  and  commonly  contains 


FIG.  167.  — Chestnuts. 


THE   FRUIT 


223 


a  seed  which  springs  from  a  single  ovule  of  one  cell  of  a 
compound  ovary,  which  develops  at  the  expense  of  all  the 
other  ovules.  The  chestnut-bur  is  a  kind  of  involucre, 
and  so  is  the  acorn-cup.  The  name 
nut  is  often  incorrectly  applied  in 
popular  language;  for  example,  the 
so-called  Brazil-nut  is  really  a  large 
seed  with  a  very  hard  testa. 

238.    The    Follicle.  —  One-celled, 
simple  pistils,  like  those  of  the  marsh 
marigold,  the  columbine,  and  a  good 
many  other   plants,   often    produce  a 
FIG. IBS. -Group of  Fom- fruit   which   dehisces    along  a   single 
cies  and  a  single  Foiiicie  suture,  usually  the  ventral  one.     Such 

of  the  Monkshood.  J 

a  fruit  is  called  a  follicle  (Fig.  168). 

239.  The  Legume.  —  A    legume   is    a   one-celled   pod, 
formed  by  the  maturing  of  a  simple  pistil,  which  dehisces 
along  both  of  its  sutures,  as  already  seen  in  the  case  of 
the  bean  pod,  and  illus- 
trated in  Fig.  271. 

240.  The  Capsule. — 
The  dehiscent  fruit 
formed  by  the  ripening 
of  a  compound  pistil  is 
called  a  capsule.     Such 
a  fruit  may  be  one- 
celled,  as  in  the  linear 
pod   of    the    celandine 
(Fig.  271),  or  several- 
celled,  as  in  the  fruit  of  the  poppy,  the  morning-glory, 
and  the  jimson  weed  (Fig.  271). 


FIG.  169.  —  Winged  Fruits. 
I,  elm  ;  H,  maple. 


224  FOUNDATIONS   OF   BOTANY 

241.  Dry  Fruits  and  Fleshy  Fruits.  —  In  all  the  cases 
discussed  or  described  in  Sects.  238-240,  the  wall  of  the 
ovary  (and  the  adherent  calyx  when  present)  ripen  into 
tissues  which  are  somewhat  hard  and  dry.     Often,  how- 
ever, these  parts  become  developed  into  a  juicy  or  fleshy 
mass  by  which  the  seed  is  surrounded  ;  hence  a  general 
division  of  fruits  into  dry  fruits  and  fleshy  fruits. 

242,  The  Stone-Fruit.  —  In  the  peach,  apricot,  plum,  and 
cherry,  the  pericarp  or  wall  of  the  ovary,  during  the  proc- 
ess of  ripening,  becomes  con- 
verted into  two  kinds  of  tissue, 
the  outer   portion   pulpy  and 
edible,    the    inner    portion    of. 
almost    stony    hardness.       In 
common   language    the    hard- 
ened inner  layer  of  the  peri- 
carp,   enclosing    the    seed,    is 
called    the    stone    (Fig.    170), 

FIG.  170.— Peach.  Longitudinal      hence  the  name  stone-fruits. 

243.    The  Pome.— The  fruit 

of  the  apple,  pear,  and  quince  is  called  a  pome.  It  con- 
sists of  a  several-celled  ovary,  —  the  seeds  and  the  tough 
membrane  surrounding  them  in  the  core,  —  enclosed  by  a 
fleshy,  edible  portion  which  makes  up  the  main  bulk  of 
the  fruit  and  is  formed  from  the  much-thickened  calyx, 
with  sometimes  an  enlarged  receptacle.  In  the  apple  and 
the  pear  much  of  the  fruit  is  receptacle. 

244.  The  Pepo  or  Gourd-Fruit.  —  In  the  squash,  pump- 
kin, and  cucumber,  the  ripened  ovary,  together  with  the 
thickened  adherent  calyx,  makes  up  a  peculiar  fruit  (with 
a  firm  outer  rind)  known  as  the  pepo.  The  relative  bulk 


THE  FRUIT 


225 


of  enlarged  calyx  and  of  ovary  in  such  fruits  is  not  always 
the  same. 

How  does  the  amount  of  material  derived  from  fleshy 
and  thickened  placentae  in  the  squash  compare  with  that 
in  the  watermelon  ? 

245.  The  Berry.  —  The  berry  proper,  such  as  the 
tomato,  grape,  persimmon,  gooseberry,  currant,  and  so  on, 
consists  of  a  rather  thin-  £„ 

skinned,  one-  to  several- 
celled,  fleshy  ovary  and  its 
contents.  In  the  first  three 

cases  above  mentioned  the  

"  --S 


"P 


FIG.  171.  *—  Cross-Section  of  an  Orange. 
a,  axis  of  fruit  with  dots  showing  cut-off 
ends  of  flbro-vascular  bundles  ;  p,  parti- 
tion between  cells  of  ovary ;  S,  seed ; 
c,  cell  of  ovary,  filled  with  a  pulp  com- 
posed of  irregular  tubes,  full  of  juice ; 
o,  oil  reservoirs  near  outer  surface  of 
rind ;  e,  corky  layer  of  epidermis. 

-  The     raspberry,    blackberry 


calyx  forms  no  part  of  the 
fruit,  but  it  does  in  the  last 
two,  and  in  a  great  number 
of  berries. 

The  gourd-fruit  and  the 
hesperidium,  such  as  the 
orange  (Fig.  171),  lemon, 
and  lime,  are  merely  de- 
cided modifications  of  the 
berry  proper. 

246.  Aggregate  Fruits. 
(Fig.  172),  and  similar  fruits  consist  of  many  carpels,  each 
of  which  ripens  into  a  part  of  a  compound  mass,  which, 
for  a  time  at  least,  clings  to  the  receptacle.  The  whole  is 
called  an  aggregate  fruit. 

To  which  one  of  the  preceding  classes  does  each  unit  of 
a  blackberry  or  of  a  raspberry  belong  ? 

Wl>at   is    the   most   important   difference   in    structure 
between  a  fully  ripened  raspberry  and  a  blackberry  ? 


226  FOUNDATIONS   OF   BOTANY 

247.  Accessory  Fruits  and  Multiple  Fruits.  —  Not  infre- 
quently, as  in  the  strawberry  (Fig.  172),  the  main  bulk  of 
the  so-called  fruit  consists  neither  of  the  ripened  ovary 
nor  its  appendages.  Such  a  combination  is  called  an 
accessory  fruit. 

Examine  with  a  magnifying  glass  the  surface  of  a  small,  unripe 
strawberry,  then  that  of  a  ripe  one,  and  finally  a  section  of  a  ripe 
one,  and  decide  where  the  separate  fruits  of  the  strawberry  are  found, 
what  kind  of  fruits  they  are,  and  of  what  the  main  bulk  of  the  straw- 
berry consists. 

The  fruits  of  two  or  more  separate  flowers  may  blend 
into  a  single  mass,  which  is  known  as  a  multiple  fruit. 
Perhaps  the  best-known  edible  examples  of  this  are  the 


i  ii  in 

FIG.  172.— I,  Strawberry  ;  II,  Raspberry  ;  III,  Mulberry. 

mulberry  (Fig.  172)  and  the  pineapple.  The  last-named 
fruit  is  an  excellent  instance  of  the  seedless  condition 
which  not  infrequently  results  from  long-continued  culti- 
vation. 

248.  Summary.  —  The  student  may  find  it  easier  to 
retain  what  knowledge  he  has  gained  in  regard  to  fruits  if 
he  copies  the  following  synopsis  of  the  classification  of 
fruits,  and  gives  an  example  of  each  kind. 


THE   FRUIT 


227 


Fruits 


r  Simple. 

Composition                   J  Aggregate. 
I  Accessory. 

[Multiple. 

r         f1- 

Fleshy              J  2. 

[s. 

Texture 

Stone 

f1' 

Dry                   |j 

14. 

ft 

Indehiscent      ^  2. 

Mode  of 

I3- 

disseminating  seed 

V 

fl. 

« 

Dehiscent         J  2. 
3. 

CHAPTER   XIX 
THE    CLASSIFICATION   OF   PLANTS1 

249.  Natural  Groups  of  Plants.  —  One  does  not  need  to 
be  a  botanist  in  order  to  recognize  the  fact  that  plants 
naturally  fall  into  groups  which  resemble  each  other  pretty 
closely,  that  these  groups  may  be  combined  into  larger 
ones  the  members  of  which  are  somewhat  alike,  and  so  on. 
For  example,  all  the  bulb-forming  spring  buttercups  2  which 
grow  in  a  particular  field  may  be  so  much  alike  in  leaf, 
flower,  and  fruit  that  the  differences  are  hardly  worth 
mentioning.  The  tall  summer  buttercups  3  resemble  each 
other  closely,  but  are  decidedly  different  from  the  bulbous 
spring-flowering  kind,  and  yet  are  enough  like  the  latter 
to  be  ranked  with  them  as  buttercups.  The  yellow 
water-buttercups4  resemble  in  their  flowers  the  two 
kinds  above  mentioned,  but  differ  from  them  greatly  in 
habit  of  growth  and  in  foliage,  while  still  another,  a 
very  small-flowered  kind,5  might  fail  to  be  recognized 
as  a  buttercup  at  all. 

The  marsh  marigold,  the  hepatica,  the  rue  anemone, 
and  the  anemone  all  have  a  family  resemblance  to  butter- 
cups,6 and  the  various  anemones  by  themselves  form 
another  group  like  that  of  the  buttercups. 

1  See  Warming  and  Potter's  Systematic  Botany,  Strasburger,  Noll,  Schenk, 
and  Schimper's  Text-Book  of  Botany,  Part  II,  or  Kerner  and  Oliver,  Vol.  II, 
pp.  616-790.  2  R.  bulbosus.  3  R.  acris.  4  R.  multifidus.  5  R.  abortive, 

6  Fresh  specimens  or  herbarium  specimens  will  show  this. 

228 


THE   CLASSIFICATION  OF  PLANTS  229 

250.  Genus  and  Species.  —  Such  a  group  as  that  of  the 
buttercups    is  called  a  genus   (plural  genera),   while  the 
various  kinds  of  buttercups  of  which  it  is  composed  are 
called  species.    The  scientific  name  of  a  plant  is  that  of  the 
genus  followed  by  that  of  the  species.     The  generic  name 
begins  with  a  capital,  the  specific  does  not,  unless  it  is  a 
substantive.     After  the  name  comes  the  abbreviation  for 
the  name  of  the  botanist  who  is  authority  for  it;  thus  the 
common  elder  is  Sambucus  canadensis,  L.,  L.  standing  for 
Linnseus.     Familiar  examples  of   genera  are   the  Violet 
genus,  the  Rose  genus,  the  Clover  genus,  the  Golden-rod 
genus,  the  Oak  genus.     The  number  of  species  in  a  genus 
is  very  various,  —  the    Kentucky  Coffee-tree  genus  con- 
tains only  one  species,  while  the  Golden-rod  genus  com- 
prises more  than  forty  species  in  the  northeastern  United 
States  alone. 

251.  Hybrids If  the  pollen  of  a  plant  of  one  species 

is  placed  on  the  stigma  of  a  plant  of  the  same  genus  but  a 
different  species,  no  fertilization  will  usually  occur.     In  a 
large  number  of  cases,  however,  the  pistil  will  be  ferti- 
lized, and  the  resulting  seed  will  often  produce  a  plant 
intermediate  between  the  two  parent  forms.     This  proc- 
ess   is    called    hybridization,   and    the    resulting    plant  a 
hybrid.     Many   hybrid   oaks   have  been  found   to  occur 
in  a  state  of  nature,  and  hybrid  forms  of  grapes,  orchids, 
and  other    cultivated   plants,  are  produced   by  horticul- 
turists at  will. 

252.  Varieties.  —  Oftentimes  it  is  desirable  to  describe 
and  give  names  to  subdivisions  of  species.     All  the  culti- 
vated kinds  of  apple  are  reckoned  as  belonging  to  one  spe- 
cies, but  it  is  convenient  to  designate  such  varieties  as  the 


230  FOUNDATIONS   OF   BOTANY 

Baldwin,  the  Bellflower,  the  Rambo,  the  Gravenstein,  the 
Northern  Spy,  and  so  on.  Very  commonly  varieties  do 
not,  as  horticulturists  say,  "  come  ;true,"  that  is  to  say,  the 
seeds  of  any  particular  variety  of  apple  not  only  are  not 
sure  to  produce  that  variety,  but  they  are  nearly  sure  to 
produce  a  great  number  of  widely  different  sorts.  Varie- 
ties which  will  reproduce  themselves  from  the  seed,  such 
as  pop-corn,  sweet  corn,  flint-corn,  and  so  on,  are  called 
races. 

Only  long  and  careful  study  of  plants  themselves  and 
of  the  principles  of  classification  will  enable  any  one  to 
decide  on  the  limits  of  the  variety,  species,  or  genus,  that 
is,  to  determine  what  plants  shall  be  included  in  a  given 
group  and  what  ones  shall  be  classed  elsewhere. 

253.  Order  or  Family.  —  Genera  which  resemble  each 
other  somewhat  closely,  like  those  discussed  in  Sect.  249, 
are  classed  together  in  one  order  or  family.  The  particu- 
lar genera  above  mentioned,  together  with  a  large  number 
of  others,  combine  to  make  up  the  Crowfoot  family.  In 
determining  the  classification  of  plants  most  points  of 
structure  are  important,  but  the  characteristics  of  the 
flower  and  fruit  outrank  others  because  they  are  more 
constant,  since  they  vary  less  rapidly  than  the  characteris- 
tics of  roots,  stems,  and  leaves  do  under  changed  condi- 
tions of  soil,  climate,  or  other  surrounding  circumstances. 
Mere  size  or  habit  of  growth  has  nothing  to  do  with  the 
matter,  so  the  botanist  finds  no  difficulty  in  recognizing 
the  strawberry  plant  and  the  apple  tree  as  members  of 
the  same  family. 

This  family  affords  excellent  illustrations  of  the  mean- 
ing of  the  terms  genus,  species,  and  so  on.  Put  in  a 


THE    CLASSIFICATION   OF   PLANTS 


231 


tabular  form,  some  of  the  subdivisions  of  the  Rose  family 
are  as  follows  : 


j  Peach  species  (many  varieties). 

Plum  genus      J  Garden  Plum  sPecies  (many  varieties). 

Wild  black  cherry  species. 
I  Garden  red  cherry  species  (many  varieties). 


I  Dwarf   wild  rose 
species. 
Sweet-brier  species. 

T    ,.  .  f  Tea  variety. 

India  rose  species       4  n  . 


Pear  genus 


Damask  rose  species. 


Pear  species 


Apple  species 


Pompon  variety,  etc. 

f  Seckel  variety. 
•<  Bartlett  variety. 
^  Sheldon  variety,  etc. 

Baldwin  variety. 
Greening  variety. 
Bellflower  variety. 
Northern  Spy  variety, 
etc. 


254,  Grouping  of  Families.  —  Families  are  assembled 
into  classes,  and  these  again  into  larger  groups.  The 
details  of  the  entire  plan  of  classification  are  too  compli- 
cated for  any  but  professional  botanists  to  master,  but  an 
outline  of  the  scheme  may  be  given  in  small  space. 

The  entire  vegetable  kingdom  is  divided  into  two  great 
divisions,  the  first  consisting  of  cryptogams  or  spore-plants, 
the  second  of  phanerogams  or  seed-plants.  Here  the  rela- 
tions of  the  various  subdivisions  may  best  be  shown  by  a 
table.1 


1  This  is,  of  course,  only  for  consultation,  not  to  be  committed  to  memory. 


232 


FOUNDATIONS   OF   BOTANY 


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Conjugates,  Desmids  and  pon 
Chlorophycece,  Green  algae. 
,  Phceophycece,  Brown  algae. 

,  Rhodophycece,  Red  algae. 
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I-H 

*s 

v 

; 

.S 

THE   CLASSIFICATION   OF   PLANTS 


233 


DIVISION  II 

PHANEROGAMS  OR 

SEED-PLANTS 


CLASS  I 

GYMNOSPERMS  or  seed-plants  with  naked  ova- 
ries, such  as  pines,  spruces,  cedars,  and  many 
other  evergreen  trees. 

f  SUBCLASS-  I 


CLASS  II 
ANGIOSPERMS  or 

seed-plants  with 
closed  ovaries 


MONOCOTYLEDONOUS 

PLANTS 

SUBCLASS  II 
DICOTYLEDONOUS 

PLANTS 


256,  The  Groups  of  Cryptogams.  —  The  student  is  not 
to  suppose  that  the  arrangement  of  cryptogams  into  the 
four  great  groups  given  in  the  preceding  table  is  the  only 
way  in  which  they  could  be  classed.     It  is  simply  one 
way  of  dividing  up  the  enormous  number  of  spore-bearing 
plants  into  sections,  each  designated  by  marked  character- 
istics of  its  own.     But  the  amount  of  difference  between 
one  group  and  another  is  not  always  necessarily  the  same. 
The    pteridophytes    and   the    bryophytes    resemble    each 
other   much  more  closely  than  the  latter  do  the  thallo- 
phytes,  while  the  myxothallophytes  are  but  little  like  other 
plants  and  it  is  extremely  probable  that  they  are  really 
animals. 

The  classes  given  in  the  table  do  not  embrace  all  known 
cryptogams,  but  only  those  of  which  one  or  more  repre- 
sentatives are  described  or  designated  for  study  in  this 
book.  Lichens  in  one  sense  hardly  form  a  class,  but  it  is 
most  convenient  to  assemble  them  under  a  head  by  them- 
selves, on  account  of  their  extraordinary  mode  of  life,  a 
partnership  between  algae  and  fungi. 

257.  The  Classes  of  Seed-Plants.  —  The  gymnosperms 
are  much  less  highly  developed  than  other  seed-plants. 


234  FOUNDATIONS   OF   BOTANY 

The  angiosperms  constitute  the  great  majority  of  seed- 
plants  (or,  as  they  have  been  more  commonly  called, 
flowering  plants).  Only  one  family  of  gymnosperms  (the 
Coniferce)  is  described  in  Part  III  of  this  book,  though 
there  are  other  families  of  great  interest  to  the  botanist, 
but  with  no  representatives  growing  wild  in  the  Northern 
United  States. 

When  people  who  are  not  botanists  speak  of  plants 
they  nearly  always  mean  angiosperms.  This  class  is  more 
interesting  to  people  at  large  than  any  other,  not  only  on 
account  of  the  comparatively  large  size  and  the  con- 
spicuousness  of  the  members  of  many  families,  but  also 
on  account  of  the  attractiveness  of  the  flowers  and  fruit 
of  many.  Almost  all  of  the  book  which  precedes  the 
present  chapter  (except  Chapter  XII)  has  been  occupied 
with  seed-plants. 

Seed-plants  of  both  classes  frequently  offer  striking 
examples  of  adaptation  to  the  conditions  under  which 
they  live,  and  these  adaptations  have  lately  received  much 
study,  and  are  now  treated  as  a  separate  department  of 
botany  (see  Part  II). 


CHAPTER   XX 
TYPES    OF  CRYPTOGAMS;    THALLOPHYTES 

258.  The   Group   Thallophytes.  —  Under  this  head  are 
classed  all    the  multitude    of   cryptogams  which  have  a 
plant-body  without  true  roots,  stems,  or  leaves.     Such  a 
plant-body  is  called  a  thallus.     In  its  simplest  form  it  con- 
sists of  a  portion  of  protoplasm  not  enclosed  in  a  cell-wall 
and  without  much  of  any  physiological  division  of  labor 
among  its  parts  (Fig.  125).     Only  a  little  less  simple  are 
such  enclosed  cells  as  that  of  Pleurococcus  (Sect.  278)  or 
one  of  the  segments  of  Oscillatoria  (Sect.  268).    The  most 
complex  thallophytes,  such  as  the  higher  algse  and  fungi, 
have  parts  definitely  set  aside  for  absorption  of  food  and 
for  reproduction.     The  latter  is  sometimes  accomplished 
by  more    than  one  process  and  is  occasionally  aided  by 
some  provision  for  scattering  the  reproductive  bodies  or 
spores  about  when  they  are  mature. 

259.  Spores.  —  Before   beginning   the    study  of   spore- 
plants  it  is  well  for  the  student  to  know  what  a  spore  is. 
A  spore  is  a  cell  which  becomes  free  and  capable  of  develop- 
ing into  a  new  plant.     Spores  are  produced  in  one  of  two 
ways :  either  asexually,  from  the  protoplasm  of  some  part 
of  the  plant  (often  a  specialized  spore-producing  portion), 
or  sexually,  by  the  combination  of  two  masses  of  proto- 
plasm, from  two  separate  plants,  or  from  different  parts  of 
the  same  plant. 

235 


236  FOUNDATIONS  OF  BOTANY 

Asexually  produced  spores  are  sometimes  formed,  each 
by  the  condensation  of  the  protoplasm  of  a  single  cell,  as 
shown  in  Fig.  174,  E.  They  are  also  formed  by  the  con- 
tents of  spore-cases  breaking  up  into  many  spores  (Fig. 
173,  B\  Fig.  210,  D).  Spores  are  sometimes  produced  by 
the  spontaneous  division  of  a  mass  of  protoplasm  into  a 
small  definite  number  of  segments  (Fig.  188,  t).  Spores 
which  have  the  power  of  moving  (swimming)  freely  are 
known  as  zoo  spores  (Fig.  179,  B). 

Sexually  produced  spores  are  formed  in  many  ways. 
One  of  the  simplest  modes  is  that  shown  in  Fig.  178, 
resulting  in  zygospores.  Other  methods  are  illustrated  in 
Figs.  185  and  187.1 

THE   STUDY   OF   SLIME  MOULDS 2 

260,  Occurrence.  —  Slime  moulds  occur  in  greenhouses,  in  tan- 
yards,  or  on  old  logs  arid  decaying  leaves  in  woods.     They  may  be 
cultivated  in  the  laboratory. 

They  have  been  described  in  their  vegetative  condition  on  page  179. 

261,  Examination  with  the  Magnifying  Glass.  —  Stemonitis  is  one 
of  the  most  available  genera  to  illustrate  the  fruiting  of  slime  moulds. 
At  maturity  the  motile  protoplasm  of  the  vegetative  stage  quickly 
transforms  itself  into  numerous  sporangia  or  spore-cases  with  dust- 
like  spores.     With  the  naked  eye  and  with  a  magnifying  glass  note 
the  color,  form,  and  feathery  appearance  of  the  spore-case  of  Stemo- 
nitis.    The  outer  wall  disappears  at  an  early  stage,  leaving  only  an 
inner   structure    and   spores.     Sketch   the  general  outline  under  a 
magnifying  glass. 

262,  Examination  with  the  Microscope.  —  With  a  low  power  of 
the  microscope  sketch  the  network  of  branching  hairs  which  com- 
pose the  structure  of  the  sporangium.     Note  the  presence  or  absence 

1  See  Vine's  Student's  Text-Book  of  Botany,  pp.  68-71. 

2  This  should  logically  precede  Sect.  258. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES 


237 


of  a  central  column.  Have  any  of  the  branches  free  tips  ?  With  a 
power  of  250  or  more  examine  the  spores.  A  much  higher  power 
may  be  used  to  advantage.  Describe  the  surface  of  the  spore. 


THE   STUDY   OF   BACTERIA 

263.    Occurrence.  —  "  Bacteria  may  occur  anywhere  but  not  every- 
where."   In  water,  air,  soil,  and  almost  any  organic  substance,  living 


FIG.  173.  —  Spore-Cases  of  Slime  Moulds. 

A,  a  group  of  spore-cases  of  Arcyria;  £,  a  spore-case  of  TricMa,  bursting  open 
and  exposing  its  spores  to  the  wind,  x  20 ;  C,  threads  of  the  same,  with  spores 
between  them,  x  250. 

or  dead,  some  species  of  plant  belonging  to  the  group  Bacteria  may 
occur.  A  small  bunch  of  hay  placed  in  a  tumbler  of  water  will,  at  a 
suitable  temperature,  yield  an  abundant  crop  in  a  few  days  or  hours. 
Raw  peas  or  beans  soaked  for  a  week  or  two  in  water  in  a  warm 
place  will  afford  a  plentiful  supply. 

264.  Cultures.  —  Pure  cultures  of  bacteria  are  commonly  made  in 
some  preparation  of  gelatine  in  sterilized  test-tubes.  Boiled  potatoes 
serve  a  good  purpose  for  simple  (but  usually  not  pure)  cultures. 

Select  a  few  small  roundish  potatoes  with  skins  entire  and  boil 
in  water  for  a  sufficient  time  to  cook  them  through.  Cut  them  in 
halves  with  a  knife  well  scalded  or  sterilized,  i.e.,  freed  from  all  living 


238  FOUNDATIONS   OF   BOTANY 

organisms  in  a  flame,  and  lay  each  on  a  saucer,  with  cut  surface  up, 
covering  each  with  a  glass  tumbler.  The  tumblers  and  saucers 
should  be  well  scalded  or  kept  in  boiling  water  for  half  an  hour  and 
used  without  wiping.  Sterilization  may  be  improved  by  baking 
them  in  an  oven  for  an  hour. 

265.  Inoculation.  —  The  culture  media  prepared  as  above  may 
now  be  inoculated.  Uncover  them  only  when  necessary  and  quickly 
replace  the  cover.  Scrape  a  little  material  from  the  teeth,  tongue, 
kitchen  sink,  floor  of  house  or  schoolroom,  or  any  other  place  you 
may  desire  to  investigate.  With  the  point  of  a  knife  blade  or  a 
needle  sterilized  in  a  flame,  inoculate  a  particle  of  the  material  to  be 
cultivated  into  the  surface  of  one  of  the  potatoes.  Several  cultures 


D  E 

FIG.  174.  —  Bacteria  stained  to  show  Cilia. 

A,  Bacillus  subtilis ;  B,  Bacillus  typhi  (the  bacillus  of  typhoid  fever) ;  C,  Bacillus 
tetani  (the  bacillus  which  causes  lockjaw)  ;  D,  Spirillum  undula;  E,  Bacillus 
tetani  forming  spores.  (All  five  are  magnified  1000  diameters.) 

may  be  made  in  this  way  and  one  or  more  left  uninoculated  as 
checks.  Another  may  be  left  uncovered  in  the  air  for  half  an  hour. 
Others  may  be  made  with  uncovered  potatoes.  Number  each  culture 
and  keep  a  numbered  record. 

Keep  watch  of  the  cultures,  looking  at  them  daily  or  oftener.  As 
soon  as  any  change  is  noticed  on  the  surface  of  a  culture,  make  a 
descriptive  note  of  it  and  continue  to  record  the  changes  which  are 
seen.  Note  the  color  of  the  areas  of  growth,  their  size,  outline,  ele- 
vation above  the  surface,  and  any  indications  of  wateriness.  Any 
growth  showing  peculiar  colors  or  other  characters  of  special  inter- 
est may  be  inoculated  into  freshly  prepared  culture  media,  using 
any  additional  precautions  that  are  practicable  to  guard  against 
contamination. 


TYPES  OF  CKYPTOGAMS;  THALLOPHYTES     239 

266.  Microscopic  Examination.  —  Examine  some  of  the  cultures. 
Place  a  particle  of  the  growth  on  a  slide,  dilute  it  with  -a  drop  of 
clear  water,  and  place  a  cover-glass  over  it.  Examine  with^  the 
highest  obtainable  power  of  the  microscope,  at  least  £  iu.  objective. 
Note  the  forms  and  movements,  also  the  sizes  if  practicable,  of  any 
bacteria  that  are  found. 


THE   STUDY   OF   OSCILLATORIA 1 

267.  Occurrence.  —  Oscillatoria   may  occur   floating   in  stagnant 
water  or  on  damp  soil  in  ditches,  roadsides,  dooryards,  paths,  or 
pots  in  greenhouses.     Other  nearly  related  plants  occur  on  surfaces 
of  ponds  sometimes  covering  considerable  areas  or  adhering  in  small 
spheres  to  submerged  vegetation.     Algse  of  this  class  are  particu- 
larly noxious  in  water  supplies,  as  they  partake  of  the  nature  of 
bacteria,  to  which  they  are  related. 

268.  Examination  with  the  Microscope.  —  After  washing  a  particle 
of  Oscillatoria  material  in  a  drop  of  water  to  remove  as  much  of  the 
earth  as  possible,  place  it  in  a  clean  drop  of  water,  pull  to  shreds 
with  needles,  cover,  and  examine  under  a  power  of  200  or  more 
diameters. 

Note  the  color  and  compare  it  with  chlorophyll  green. 

The  filament  is  not  one  plant,  but  each  of  the  cells  which  com- 
pose it  is  one  plant.  They  are  packed  together  in  the  filament  like 
coins  and  sometimes  may  be  found  separating  singly.  The  usual 
mode  of  reproduction  is  by  the  separation  of  a  number  of  adhering 
cells  as  a  short  filament  from  one  end  of  a  longer  one,  and  this 
increases  in  length  by  the  dividing  of  its  individual  cells. 

269.  Movement.  —  At  ordinary  temperatures,  favorable  to  growth, 
movement  may  be  observed  in  the  filaments.     Describe  the  move- 
ment.    What  has  it  to  do  with  the  name  of  the  plant  ? 

1  A  genus  of  the  class  Schizophycese. 


240 


FOUNDATIONS   OF  BOTANY 


THE   STUDY   OF   DIATOMS 

270.    Occurrence.  — Diatoms  of  different  species  may  be  found  in 
sediment  in  water  in  various  kinds  of  places  or  mixed  with  or 

adhering  to  fresh-water  or  ma- 
rine algae,  in  ponds  and  ditches 
or  on  sand  or  earth  at  the 
bottom  of  clear  brooks.  In  the 
last  place  they  may  be  detected 
with  the  eye,  forming  a  yellow- 
ish coloring.  They  may  often 
be  obtained  by  straining  hy- 
drant water.  Where  diatoms 
have  been  very  abundant  their 
remains  sometimes  form  beds 
of  rock,  and  fossil  diatoms 
compose  some  of  the  polishing 
powders  of  commerce. 

271.  Microscopical  Examina- 
tion of  Diatoms.  —  Place  a  drop 
of  water  containing  diatoms  on 
a  slide  and  put  a  cover-glass 
over  it.  Examine  with  a  power 
of  200  or  more  diameters.  Dia- 
toms occur  singly/  resembling 
triangles,  wheels,  boats,  rods-, 
and  a  great  variety  of  other 
forms  (Fig.  176),  or  adhering 
in  long  bands,  as  spokes  of  a 
wheel,  etc.  The  boat-shaped 
kinds  are  among  the  common- 
est. The  color  of  the  contents 
is  yellowish.  The  cell-wall  is 
encrusted  with  a  shell  of  silica 
whose  surface  is  covered  with  beautiful  markings,  dots  or  lines, 
which  are  conspicuous  in  some  species,  in  others  so  minute  that  the 
most  powerful  microscopes  are  required  to  detect  them.  By  boiling 


FlG.  175.  —  Schlzophycex. 
A,  a  filament  of  Calothrix,  reproducing  by 
hormogonia,  h,  segmented  portions  which 
escape  from  the  sheath  of  the  filament  ; 
B,  Rlvularla.  (Both  A  and  B  greatly 
magnified.) 


TYPES  OF  CRYPTOGAMS ;  THALLOPHYTES 


241 


in  nitric  acid,  the  cellulose  wall  and  its  contents  may  be  destroyed 
and  the  markings  of  the  siliceous  shell  more  easily  observed.  Each 
diatom  consists  of  a  single  cell. 

272.  Movements  of  Diatoms.  —  Living  diatoms  exhibit  a  peculiar 
power  of  movement.  In  the  boat-shaped  species  the  movement  is 
much  like  that  of  a  row-boat,  forward  or  backward. 


THE   STUDY   OF   SPIROGYRA 

273.  Occurrence.  —  Spirogyra,  one  of  the  plants  commonly  known 
as  pond-scum,  or  "  frog-spit,"  occurs  widely  distributed  throughout 
the  country  in  ponds,  springs, 

and  clear  streams.  It  is  of  a 
green  or  yellowish-green  color, 
and  in  sunny  weather  usually 
floats  on  or  near  the  surface  of 
the  water,  buoyed  up  by  the 
numerous  oxygen  bubbles  which 
it  sets  free.  It  may  be  found 
flourishing  in  unfrozen  springs, 
even  in  midwinter. 

274.  Examination  with  the 
Magnifying    Glass.1  —  Float    a 
little  of  the  material  in  a  white 
plate,  using  just  water  enough 
to  cover  th6  bottom  of  the  latter. 
Study  with  the  magnifying  glass 
and  note  the  green  color  of  the 
threads  and  their  great  length 
as  compared  with  their  thick- 
ness. Are  all  the  filaments  about 


FIG.  176.  —  A  Group  of  Diatoms. 

A,  Achnanthes;  B,  Cocconema; 
C,  Meridian;  D,  Pleurosigma. 


equal  to  each  other  in  diameter  ? 

Handle  a  mass  of  the  material  and  describe  how  it  feels  between 
the  fingers. 

275.  Examination  with  the  Microscope.  —  Mount  in  water  under 
a  large  cover-glass  and  examine  first  with  a  power  of  about  100 

1  Consult  Huxley's  Biology  and  Spalding's  Introduction  to  Botany. 


242 


FOUNDATIONS   OF   BOTANY 


diameters,  then  with  a  power  of  200  diameters  or  more.  Note  the 
structure  of  the  filaments.  Of  what  is  each  made  up?  Compare 
with  the  structure  of  Oscillatoria. 

Move  the  slide  so  as  to  trace  the  whole  length  of  several  filaments, 
and,  if  the  unbroken  end  of  one  can  be  found,  study  and  sketch  it. 

Study  with  the  higher  power  a  single 
cell  of  one  of  the  larger  filaments  and 
ascertain  the  details  of  structure.  Try 
to  discover,  by  focusing,  the  exact  shape 
of  the  cell.  How  do  you  know  that 
the  cells  are  riot  flat?  Count  the  bands 
of  chlorophyll.  The  number  of  bands 
is  an  important  characteristic  in  dis- 
tinguishing one  species  from  another. 
Run  in  five-per-cent  salt  solution  at 
one  edge  of  the  cover-glass  (withdraw- 
ing water  from  the  other  edge  with  a 
bit  of  blotting  paper).  If  any  change 
in  the  appearance  of  the  cell  becomes 
evident,  make  a  sketch  to  show  it. 
What  has  happened  to  the  cell-con- 
tents? Explain  the  cause  of  the 
change  by  reference  to  what  you  know 
of  osmose. 

On  a  freshly  mounted  slide  run 
under  the  cover-glass  iodine  solution, 
a  little  at  a  time,  and  note  its  action 
on  the  nucleus.  Is  any  starch  shown 
to  be  present?  If  so,  just  how  is  it 
distributed  through  the  cell? 

276.  Reproduction  of  Spirogyra.  — 
The  reproductive  process  in  Spirogyra 
is  of  two  kinds,  the  simplest  being  a  process  of  fission,  or  cell- 
division.  The  nucleus  undergoes  a  very  complicated  series  of 
transformations,  which  result  in  the  division  of  the  protoplasmic 
contents  of  a  cell  into  two  independent  portions,  each  of  which  is 
at  length  surrounded  by  a  complete  cell-wall  of  its  own.  In  Fig.  176 


FIG.  177.  — Process  of  Cell-Multi- 
plication in  a  Species  of  Pond- 
Scum.  (Considerably  magnified.) 

A,  portion  of  a  filament  partly 
separated  at  a  and  completely 
so  at  b ;  B,  separation  nearly 
completed,  a  new  partition  of 
cellulose  formed  at  a;  C, 
another  portion  more  magni- 
fied, showing  mucous  covering 
d,  general  cell-wall  c,  and  a 
delicate  membrane  a,  which 
covers  the  cell-contents  b. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES 


243 


the  division  of  the  protoplasm  and  formation  of  a  partition  of 
cellulose  in  a  kind  of  pond-scum  are  shawn,  but  the  nucleus  and  its 
changes  are  not  represented. 

Another  kind  of  reproduction,  namely  by  conjugation,  is  found  in 
Spirogyra.  This  process  in  its  simplest  form  is  found  in  such 
unicellular  plants  as  the  desmids 
(Fig.  178).  Two  cells  (apparently 
precisely  alike)  come  in  contact, 
undergo  a  thinning-down  or  absorp- 
tive process  in  the  cell-walls  at  the 
point  of  contact,  and  finally  blend 
their  protoplasmic  cell-contents,  as 
shown  in  the  figure,  to  form  a  mass 
known  as  a  spore,  or  more  accu- 
rately a  zygospore,  from  which,  after 


FIG.  178.— Conjugation  of  Cells  of  Green  Algae.     (Much  magnified.) 

I.  Conjugation  of  Desmids.  A,  a  single  plant  in  its  ordinary  condition;  B,  empty 
cell-wall  of  another  individual ;  C,  conjugation  of  two  individuals  to  form  a 
spore- by  union  of  their  cell-contents. 

II.  Conjugation  of  Spirogyra.  A,  two  filaments  of  Spirogyra  side  by  side,  with 
the  contents  of  adjacent  cells  uniting  to  form  spores,  z.  At  the  bottom  of  the 
figure  the  process  is  shown  as  beginning  at  the  top  as  completed,  and  the  cells 
of  one  filament  emptied  ;  £,  a  single  filament  of  another  kind  of  Spirogyra, 
containing  two  spores,  one  lettered  z.  (A  magnified  240  diameters,  B  150 
diameters.) 

a  period  of  rest,  a  new  individual  develops.  In  Spirogyra  each 
cell  of  the  filament  appears  to  be  an  individual  and  can  conjugate 
like  the  one-celled  desmids.  It  is  not  easy  to  watch  the  process, 
since  the  spore-formation  takes  place  at  night.  It  is  possible, 


244 


FOUNDATIONS   OF   BOTANY 


however,  to  retard  the  occurrence  of  conjugation  by  leaving  the 
Spirogyra  filaments  in  very  cold  water  over  night,  and  in  this  way 
the  successive  steps  of  the  conjugating  process  may  be  studied  by 
daylight.  In  such  ways  the  series  of  phenomena  shown  in  Fig. 
178,  II,  has  been  accurately  followed.  If  the  student  cannot  follow 
these  operations  under  the  microscope,  he  may,  at  least,  by  looking 
over  the  yellower  portions  of  a  mass  of  Spirogyra  find  threads  con- 
taining fully  formed  zygospores,  like  those  shown  in  B,  Fig.  178. 


THE    STUDY   OF   PLEUROCOCCUS 

277.  Occurrence. — Pleurococcus  may   be   found   on   old   fences, 
roofs,  and  many  similar  places,  particularly  on  the  bark  of  the  north 
side  of  trees.    The  individual  plants  cannot  be  detected  by  the  naked 
eye,  but  when  grouped  in  masses  they  form  a  powdery-green  covering 
over  indefinite  areas  of  bark.     Plenty  are  seen  where  it  is  moist. 

278.  Microscopical  Examination  of  Pleurococcus.  —  Scrape  a  minute 
quantity  of  Pleurococcus  from  a  specimen  on  bark,  place  it  in  a  drop 
of  water  on  a  slide,  distributing  it  slightly  in  the  water,  lay  on  it 

a  cover-glass  and  ex- 
amine with  a  power  of 
200  or  more  diameters. 
Sketch  with  the  cam- 
era lucida  one  of  the 
largest  cells,  some  of 
intermediate  size,  and 
one  of  the  smallest, 
beside  several  divisions 
of  the  stage  microm- 
eter. 

Note  the  clearly  de- 
fined cell-wall  of  cel- 
lulose, enclosing  the 
protoplasmic  contents, 
usually  green  through- 
Do  any  cells  show  a  nucleus  like  that  in  Fig.  179,  A  ? 


FlG.  179.  —  Two  Cells  of  Protococcus. 
(Greatly  magnified.) 

A,  a  spherical  cell  of  the  still  form  ;  B,  a  motile  cell 
with  its  protoplasm  enclosed  in  a  loose  cell-wall  and 
provided  with  two  cilia. 


out. 


Test  the  cells  with  iodine  solution  for  starch. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES    245 

"Note  that  in  reproduction  the  cell-contents  in  many  individuals 
has  divided  into  two  parts  which  become  separated  from  each  other 
by  a  cellulose  partition.  Each  of  these  again  divides,  and  the  proc- 
ess continues  until  thirty-two  or  more  cells  may  be  found  in  one 
mass  or  they  may  fall  apart  at  an  earlier  stage. 

279.  Nutrition  of  Pleurococcus.  —  Pleurococcus  can  nourish  only 
with  an  abundance  of  light  and  moisture.    In  daylight  it  can  absorb 
carbon  dioxide  and  fix  carbon  (giving  off  the  oxygen  at  the  same 
time  as  bubbles  of  oxygen)  and  can  assimilate  mineral  substances. 
It  is  a  capital  example  of  an  individual  cell  capable  of  independent 
existence. 

280.  Motile  Forms.  —  No  motile  form  is  known  in  Pleurococcus. 
Hcematoccus,  often  known  as  Protococcus  (Fig.  179),  is  a  better  object 
for  study  than  Pleurococcus.     It  may  sometimes  be  found  in  water 
of  stagnant  pools,  particularly  those  which  contain  the  drainage  of 
barnyards  or  manure-heaps,  in  mud  at  the  bottom  of  eaves-troughs, 
in  barrels  containing  rain-water,  or  in  water  standing  in  cavities  in 
logs  or  stumps.     Its  presence  is  indicated  by  a  greenish  or  some- 
times by  a  reddish  color.     It  is  sometimes  found  in  an    actively 
swimming  condition,  in  which  case  each  cell  is  called  a  zoospore. 

THE   STUDY   OF   VAlJCHERIA 

281.  Occurrence.  —  Species    of    Vaucheria   are   found   in   ponds, 
streams,  and  pools,  immersed  or  floating  like  Spirogyra  and  at  all 
seasons  may  be  sought  in  greenhouses,  where  they  grow  on  the  moist 
earth  of  beds  and  pots,  forming  a  green  felt. 

282.  Examination  with  the  Magnifying  Glass.  —  The  magnifying 
glass  will  show  the  growth    of    Vaucheria  to  consist  of  numerous 
green  filaments  similar  to  those  of  Spirogyra.     Select  a  srnall  portion 
and  spread  out  the  filaments  carefully  in  a  drop  of  water  on  a  slide. 
Does  the -glass  reveal  any  indications  of  cross-partitions,  of  branch- 
ing, or  of  fruiting  organs  as  short  lateral  branches  ?     Does  it  show 
the  form  or  arrangement  of  the  green  coloring  matter? 

283.  Examination   with   the   Microscope.  —  Prepare    as   directed 
for  the  magnifying  glass  and  place  a  cover-glass  over  the  prepara- 
tion, with  sufficient  water.     With  the  lowest  power   observe  the 


246 


FOUNDATIONS   OF   BOTANY 


continuity  of  the  cell-cavity  and  (in  young  plants  growing  on  soil) 
search  for  root-like  portions,  in  those  growing  in  water  for  branch- 
ing portions,  and  fruiting  organs  in  the  form  of  swellings  or  short 
lateral  branches. 

With  a  power  of  about  thirty  to  sixty  diameters  sketch  a  selected 
plant  of   moderate    extent    as.   nearly  complete   as  possible   or  else 


FIG.  180. —  Vaucheria  synandra. 

A,  a  filament  with  archegonia  and  antheridia  (considerably  magnified) ;  B,  part 
of  same  much  more  highly  magnified ;  o,  oogonium ;  a,  antheridium ;  C,  a 
later  stage  of  B ;  Z>,  end  of  a  filament  with  a  zoospore,  z,  escaping  (highly 
magnified). 

sketch  a  portion  showing  the  branching  and  a  root-like  portion. 
Note  and  indicate  the  absence  or  presence  and  arrangement  of 
chlorophyll.  Can  Vaucheria  probably  use  carbon  dioxide? 

284.  Reproduction  in  Vaucheria.  —  Make  an  outline  sketch  of 
fruiting  organs,  if  found.  See  if  any  filaments  can  be  found  with 
the  contents  massing  or  escaping  at  the  tips.  In  some  species 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES     247 

zoospores  are  formed  in  this  way,  having  their  entire  surface  clothed 
with  cilia.  They  are  the  largest  motile  cells  known.  In  other  spe- 
cies a  portion  of  the  filament  is  separated  and  cut  off  by  a  cell-wall. 
Such  spores  soon  germinate  and  may  be  found  in  various  stages  of 
growth.  They  often  serve  for  propagation  through  several  genera- 
tions before  spores  are- produced  by  fertilization. 

With  a  power  of  about  200  diameters  sketch  a  portion  of  a  fila- 
ment to  show  the  form  and  location  of  chlorophyll.  Sketch  the 
fruiting  organs  in  detail,  if  any  can  be  found.1 

Antheridia  and  oogonia  are  formed  near  together  on  the  same 
filament.  The  antheridium  is  a  cell  forming  the  terminal  portion 
of  a  short  branch,  which  is  rather  slender,  straight  or  curved.  Its 
contents  form  numerous  minute  antherozoids,  each  with  two  cilia. 
The  cilia  can  be  seen  only  with  great  difficulty,  if  at  all,  but  their 
presence  is  indicated  by  their  active  movements. 

The  oogonium  is  a  short,  somewhat  spheroidal  branch  separated 
by  a  cross-partition  at  the  base.  The  cell-wall  becomes  ruptured  at 
the  tip,  allowing  the  entrance  of  the  antherozoids  by  which  it  is 
fertilized.  After  fertilization  a  cell-wall  is  formed  about  the  oosphere, 
and  it  matures  as  an  oospore  and  enters  upon  a  period  of  rest. 

THE    STUDY   OF   NITELLA 

285.  Occurrence.  —  Nitella  is  a  green  plant  growing  attached  to 
the  bottom  of  ponds  and  streams,  usually  in  shallow  water.     It  is 
not  common  everywhere  but  is  widely  distributed.     Chara  is  similar 
and  may  be  used  as  a  substitute  but  is  more  complicated. 

286.  General   Aspect.  —  With   the   naked   eye    and   a   magnify- 
ing glass  note  the  general  aspect  of  Nitella,  the  length  of  the  stem- 
like  portions,  from  the  root-like  parts  to  the  tip,  the  length  of  some 
of  the  joints  (internodes),  the  arrangement  of  leaf-like  and  branch- 
like  portions. 

287.  Protoplasm.  —  Examine  the  cells  of  sterns  or  leaves  under  a 
low  power.     Select  a  vigorous  cell  of  moderate  size  and  examine 

1  Goebel  states  that  the  formation  of  the  fruiting  organs  begins  in  the  even- 
ing, is  completed  the  next  morning,  and  that  fertilization  takes  place  during 
the  day  between  ten  and  four  o'clock. 


248 


FOUNDATIONS   OF   BOTANY 


under  a  power  of  200  or  more  diameters.  Select  the  terminal  cell 
of  the  leaf  if  Cham  is  used.  The  protoplasm  is  nearly  colorless  but 
usually  contains  bodies  which  can  be  seen  moving  in  the  current  of 
protoplasm.  The  protoplasm  will  show 
normal  activity  at  the  temperature  of  a 
comfortable  living  room.  By  focusing,  see 
if  the  current  of  protoplasm  can  be  detected 
moving  in  more  than  one  direction. 

Note  the  form  and  arrangement  of  the 
chlorophyll  and  any  places  lacking  chloro- 
phyll, and  see  if  you  can  tell  whether  the 
arrangement  has  any  relation  to  the  current 
of  protoplasm.  With  a  low  power  trace  the 
course  in  several  cells.  How  many  cells  con- 
stitute each  internode  of  Nitella  1  If  Chara 
is  used,  iriternodes  will  be  found  to  be 
covered  with  a  layer  of  many  corticating 
cells.  Under  a  high  power  compare  the 
general  structure  of  node  and  internode  and 
see  if  the  attachment  of  leaves  and  branches 
can  be  clearly  determined.  Compare  the  tip 
of  a  leaf  with  the  tip  of  a  stem  or  branch 
if  the  material  permits.  Are  the  fruiting 
organs  produced  on  the  stems  or  the  leaves? 
288.  Antheridia.  —  The  antheridia  are 
globular  bodies,  bearing  male  fertilizing 
cells  and  becoming  red  at  maturity  (Fig. 
182).  Eight  cells  compose  the  outer  wall. 
They  have  radial  lines  indicating  folds  and 
join  one  another  by  irregular  sutures.  Xote 
a  round  spot  in  the  middle  of  each  cell 
which  marks  the  point  of  attachment  within 
of  the  stalk  on  which  antherozoid-producing  cells  are  borne. 

289.  Oogonia.  —  The  egg-shaped  fruits,  known  as  oogonia  (Fig. 
182),  are  borne  near  the  antheridia  in  monoecious  species.  Count 
the  number  of  pointed  cells  which  constitute  the  "  crown  "  of  the 
fruit,  Does  each  tip  consist  of  one  or  two  short  cells  ?  Examine 


FIG.  181.  —  End  of  a  Main 
Shoot  of  Chara.  (About 
natural  size.) 


TYPES  OF  CRYPTOGAMS;  THALLOPIIYTES 


249 


the  surface  of  the  enveloping  cells  which  enclose  the  spore.  What 
is  their  number  and  form  ?  What  is  their  relation  to  the  cells  form- 
ing the  crown  ?  Focus  so  as  to  see  the  large  egg-cell  (oosphere  or 
oospore)  which  constitutes  the  center  of  the  fruit.  Can  you  determine 
anything  regarding  its  contents  ? 

Search  for  young  oogonia  and  if  practicable  describe  and  draw 
them  in  several  stages  of  development.  Their  structure  can  be  seen 
much  more  easily  than  that  of  the 
antheridia.  Make  drawings  to  illus- 
trate various  details  of  structure. 

290.  Characeae.  —  Nitella 
and  Char  a  are  the  genera 
composing  the  group  Chara- 
cece,  a  group  of  green  algee 
differing  widely  from  any 
others.  They  show  in  a  won- 
derful manner  simplicity  of 
cell-structure  with  a  high 
degree  of  organization.  FIG.  m- Part  of  a  Leaf  of  rig.  isi. 

,      j.    ,  (Considerably  magnified.) 

Scarcely   less    wonderful    are    a)antheridium;  0,0ogonium.  Atthe 

the     Care     and     precision    with         right  are  a  young  antheridium  and 

archegonium. 

which  botanists  have  worked 

out  their  life  history.  As  a  study  in  evolution  the  Characece 
may  be  considered  as  representing  the  highest  develop- 
ment attained  along  the  line  of  filamentous  green  algse, 
which,  while  preserving  their  algal  characteristics,  are 
comparable  in  a  remarkable  degree  with  moss-  and  fern- 
plants  and  with  seed-plants.  Every  cell  in  the  plant  has 
been  accounted  for  and  is  understood  in  regard  to  origin, 
relationship,  and  function.  With  harmony  of  structure 
throughout,  it  has  organs  comparable  to  root,  stem,  and 
leaf  in  seed-plants,  each  with  characteristic  structure  and 


250 


FOUNDATIONS   OF   BOTANY 


mode  of  growth.  The  stem  has  nodes  and  internodes. 
The  stem  increases  by  the  growth  of  an  apical  cell,  but 
growth  in  length  depends  chiefly  on  the  elongation  of  each 
internodal  cell  instead  of  the  multiplication  of  numerous 
internodal  cells. 


THE   STUDY   OF   ROCKWEED1 

291.    Occurrence.  —  The    common  rockweed  is  abundant  every- 
where on  rocks,  between  high  and  low  tide,  on  the  New  England 
coast  and  southward. 

292.  The  Frond.  —  A  plant  of  rockweed 
consists  mostly  of  a  growth  which  is  some- 
what leaf-like,  but,  in  fact,  stem  and  leaf 
are  not  separately  developed,  and  the  growth 
is  therefore  called  a  thallus.     This  combined 
stem    and    leaf    has    many    flat    leathery 
branches  which  are  buoyed  up  in  the  water 
by  air-bladders.     Cut  one  of  the  bladders 
open  and  note  its  form  and  appearance.  Note 
whether  they  occur  singly  or  how  grouped. 
Note  the  prominent  midrib  running  through- 
out the  middle  of  each  branch.     Examine 
the  swollen  tips  of  some  of  the  branches  and 
note  their  peculiarities.     Sketch  a  portion 
of  a  frond  to  show  the  characteristics  so  far 
noted. 

293.  Reproduction.  —  Cut  across  through 
the  middle  of  one  of  the  swollen  fruiting 
tips.      Note  the  fruiting   papillae    (concep- 
tacles)  as  they  appear  in  this  section,  and 
make  a  simple  sketch  to  show  their  position. 

Select  some  plants  with  brighter  colored 

FIG.  183.— Part  of  Thallus  of    tips  and  some  less  bright,  if  any  difference 
a  Kockweed  (Fucus  platy- 


carpus) ,  natural  size.  The 
two  uppermost  branchlets 
are  fertile. 


1  Fucus  vesiculosus  is  the  most  available  species. 
Others  may  be  substituted. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES 


251 


FIG.  184.  —  Kockweed  (Fucus). 


zoids  from  same,  x  330. 


can  be  detected.  After  making  the 
microscopic  examination  which  follows, 
note  what  correspondence  of  structure 
with  color  has  been  observed.  Cut  very 
thin  sections  through  fruiting  tips  from 
different  plants,  keeping  those  from  each 
plant  separate.  Be  sure  that  some  of 
the  cuts  pass  through  the  conceptacle  as 
near  the  middle  as  possible. 

Examine  with  a  power  of  about  sixty 
diameters  sections  from  different  fronds, 
searching  for  one  kind  containing  rather 
large  egg-shaped  cells  and  another  con- 
taining bundles  of  numerous  smaller 

sac-shaped  cells.  With  a  power  of  200  ^,  antheridia  borne  on  branch- 
diameters  Study  the  details  of  the  sec-  ing  hairs,  X160;  S,  anthero- 
tions.  Note  the  character  of  the  cells 
forming  the  surface  of  the  frond,  those 
of  the  inner  structure,  and  those  limit- 
ing the  cavity  of  the  conceptacle.  In  a 
conceptacle  cut  through  the  middle  note 
the  form  of  the  orifice.  Examine  the 
slender  hairs  or  filaments  (paraphyses} 
which,  arising  at  right  angles,  line  the 
walls  of  the  conceptacle. 

294.    Oogonia    and    Antheridia.  —  In 
conceptacles  containing  egg-shaped  cells 
(oogonia)  note  the  form, 
mode  of  attachment  (ses- 
sile or  stalked),  and  dif- 
ferent stages  of  develop- 
ment.    At  maturity  the 
contents  are  divided, 
forming  eight  oospheres; 
but  not  all  can  be  seen  FIG.  185.  —  Rockweed  (^MCMS). 

at  once,  some  being  ke_^>°ogonium,  its  contents  dividing  into  eight  oospheres, 
x  160 ;  B,  an  oosphere,  escaped,  surrounded  by  an- 
neath  the  others.  therozoids,  x  ieo. 


252 


FOUNDATIONS  OF  BOTANY 


In  conceptacles  of  the  other  kind  examine  the  numerous  small 
sac-shaped  cells'  (antheridia).  At  maturity  the  contents  of  each 
divide  to  form  numerous  very  minute  motile  antherozoids,  each  with 
two  delicate  hairs  or  cilia.  Dissect,  by  picking  and  by  friction  under 

cover-glass,  a  bunch  of 
antheridia  and  note 
the  branching  fila- 
ments upon  which 
they  are  borne. 

Make  drawings  to 
illustrate  the  various 
points  of  structure. 

295.  Number  of 
Antherozoids  required 
for  Fertilization. — The 
bulk  of  an  oosphere 
has  been  estimated 
equal  to  that  of  thirty 
thousand  to  sixty 
thousand  antherozoids, 
but  apparently  an 
oosphere  may  be  fer- 
tilized by  only  one 
antherozoid.  Yet  a 
large  number  swarm 
around  each  oosphere 
after  both  have 
escaped  from  the  con- 
ceptacles, and  often 
their  movements  are 
so  active  as  to  cause  the  rotation  of  the  oosphere.  The  process  of 
fertilization  may  be  discerned  in  fresh  material  by  squeezing 
oospheres  and  antherozoids  from  their  respective  conceptacles  into 
a  drop  of  water  on  a  slide.  In  some  species,  as  Fucus  platycarpus 
(Fig.  186),  antheridia  and  oogonia  are  found  in  the  same 
conceptacle. 


FlG.  186.  — Transverse  Section  of  Conceptacle  of  a 
Rockweed  (Fucus  platycarpus).    (x  about  35  ) 

h,  hairs  ;  a,  antheridia  ;  o,  oogonia. 


TYPES   OF   CRYPTOGAMS;   THALLOPHYTES  253 


THE   STUDY   OF   NEMALION 

296.  Occurrence.  —  Seven  or  eight  species  of  Nemalion  are  known 
in  the  world,  but  only  one l  is  widely  diffused,  being  found  in  Europe 
and  on  the  New  England  coast  from  Rhode  Island  northward.     It 
grows   in  salt  water  attached  to  exposed  rocks  at  low-water  mark. 
Nemalion  represents  the  largest  of  the  groups  of  algse,  nearly  all  of 
which  live  in  salt  water  and  have  the  characteristic  color  ;  but  a  few 
live  in  fresh  water. 

297.  Color.  —  Fresh  specimens  or  those  properly  dried  for  the 
herbarium  show  the  color  which  is  characteristic  of  the  great  group 
to   which   Nemalion  belongs.      Dried   specimens  of   "  Irish  moss " 
(Chondrus)  and  many  other  species  furnish  good  illustrations.    There 
are  many  variations  of  shade  and  intensity. 

Place  a  piece  of  a  fresh  or  dried  specimen  of  some  species  in  a 
beaker  of  fresh  water  over  night  or  longer  and  note  the  color  of  the 
solution  and  of  the  treated  specimen.  Treat  another  piece  similarly 
with  alcohol.  A  few  genera  related  to  Nemalion  grow  in  fresh 
water.  What  do  you  infer  regarding  their  color  ? 

298.  Form    and    General    Character.  —  Examine    specimens    of 
Nemalion  and  note  the  size,  shape,  mode  of  branching,  nature,  or 
consistency  of  their  substance.     Examine  a  fragment  of  the  plant 
with  a  power  of  about  sixty  diameters  and  note  how  the  structure 
differs  from  what  it  appears  to  be  to  the  naked  eye.    Do  cells  appear 
more  densely  packed  or  differently  colored  at  any  points? 

299.  Structure.  —  From  a   small  portion  of   the  plant  cut  thin 
longitudinal  and  transverse  sections  or  pull  it  to  pieces  with  needles 
so  as  to  expose  the  inner  portion.     Place  on  a  slide  under  a  cover- 
glass  in  a  drop  of  water.     With  a  power  of  about  250  diameters  or 
more  examine  the  general  structure  of  the  frond,  as  shown  by  a  slide 
prepared  as  above.     Note  the  central  portion  (axis')  of  the  frond  as 
dissected  out,  consisting  of  long,  slender,  thread-like  cells.    Examine 
and  draw  the  branching  rows  of  cells  which,  radiating  from  the 
axis,  form  the  surrounding  outer  structure  of  the  frond.     Note  the 
tips  of  .these  branches  and  look  for  the  fruiting  organs  and  fruit 
(spores). 


254 


FOUNDATIONS   OF   BOTANY 


FIG.  187.  — Portions  of  Thallus  of  a  Red  Alga 
(Chantransia).    (Much  magnified.) 

A,  filaments  with  antheridia,  a  ;  B,  young  recep- 
tive hair,  or  trichogyne,  t ;  C  and  D,  successive 
stages  in  the  growth  of  the  clustered  fruit,/. 

the  spores  at  maturity.     Are  they  naked 
envelope  ?     Are  they  arranged  in  masses, 


300.  Organs  for  Repro- 
duction. —  The    fruiting 
organs   are   to   be   sought 
on  the  radiating  branching 
filaments  and  are  usually 
produced    in    great    abun- 
dance during  the  summer. 
Various  stages  of  develop- 
ment may  be  expected  at 
a  given  time.    The  anther- 
ozoids    are   small   spheres 
without  cilia,    non-motile, 
with  a  thin  cell-wall.   Look 
for  cells  in  which  they  are 
formed  (antkeridia),  occur- 
ring in  groups  at  the  tips 
of  the  branches.    Compare 
these  with  the  vegetative 
cells. 

301.  Spore -Production. 
— Look  for  spore-producing 
organs  in   various  stages. 
In  the  young  stage  at  the 
time   of    fertilization,    an- 
therozoids,  carried  by  cur- 
rents   of    water,    may    be 
found  adhering.     Note  the 
shape  of  the  tip  (trichogyne} 
and  the  base  (carpogonituri), 
and  find  whether  there  is 
any    partition    separating 
them  at  this  stage.     Draw 
or    describe    a    few    later 
stages  in  development,  and 
note   the    arrangement   of 
or  enclosed  in  any  sort  of 
chains,  or  otherwise  ? 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES 


255 


302.  Other  Florideae.  —  Nemalion  represents  one  of  the  simplest 
modes  of  fruiting  in  the  red  algae.     In  others  there  is  great  variety  in 
structure    and  great  complication  in  the  mode  of  fruiting.     Some 
species  of  Polysiphonia  (or  Dasya)  may  well  be  studied  in  compari- 
son with  Nemalion  and  in  further    illustration  of   this    important 
group.1     Understanding  that  a  siphon,  in  algae,  is  a  row  of  cells,  end 
to  end,  study  the  structure  of  a  plant  of  Poly- 
siphonia as  illustrating  its  name.     How  many 

siphons  are  there  ?  Do  the  main  branches 
have  any  other  cells  covering  the  surface  (cor- 
ticating  cells)  ? 

Note  the  tufts  of  repeatedly  forking,  one- 
siphoned  filaments. 

303.  Fruiting  of  Polysiphonia.  —  The  anther- 
idia  are  to  be  sought  on  the  branching  fila- 
ments just  mentioned.     Note  how  they  differ 
from  those  of  Nemalion.     The  clustered  fruits 
or  cystocarps  will  be  recognized  as  ovoid-  © 
globose  or  urn-shaped  bodies  attached 
externally  to  the  frond.     Note  whether  € 
the  group  of  spores  is  naked  or  otherwise,        @ 
whether  the  spores  are  produced  singly 

or  in  chains  ;  how  attached ;  shape. 

Many  Floridece  have  another  kind  of 
fruiting  bodies,  spores  produced  without 
fertilization,  coordinate  with  the  asexual 
spores  of  black  mould  (see  Sect.  308). 
In  Florideae,  such  spores  are  usually 
found  in  fours  and  are  called  tetraspores. 

Are  tetraspores  usually  found  on  separate  plants  ? 

In  Polysiphonia  the  tetraspores  appear  to  be  formed  in  threes 
(tripartite},  the  fourth  being  underneath  the  three.  When  found, 
describe  their  position  and  arrangement. 

304.  Algae.  —  Diatom,    Oscillatoria,    Pleurococcus,    8pi- 
rogyra,  Vaucheria,  Nitella,  Fucus,  Nemalion,  these    eight 

1  It  is  desirable  also  to  exhibit  fresh  or  pressed  specimens  of  various  genera 
to  show  their  general  aspect. 


FIG.  188. 

A,  spores  of  Nemalion  (greatly 
magnified);  £,  portion  of 
thallus  of  a  red  alga,  Lejo- 
Hsia,  with  tetraspores,  t. 


256  FOUNDATIONS  OF  BOTANY 

plants  which  we  have  just  studied,  are  types  of  several 
families  of  plants  which  together  make  the  great  group 
called  AlgcjR.  Something  of  its  importance  in  nature  is 
indicated  by  these  facts :  The  number  of  known  species  is 
about  12,000.  In  size,  the  individuals  in  various  species 
range  from  a  single  cell  of  microscopic  dimensions,  as  in 
Pleurococcus,  to  the  giant  kelp  of  California  which  reaches 
a  length  of  more  than  1000  feet.  The  form  ranges  from  a 
simple  spherical  cell  as  in  Pleurococcus  to  an  extensive, 
branching  cell  in  Vaucheria  and  its  allies,  specialized 
organs  in  the  form  of  root,  stem,  leaf,  air-bladder,  and 
fruiting  organs  in  Sargassum,  which  is  an  ally  of  Fucus. 

The  algae  illustrate  a  series  of  modes  of  propagation 
from  simple  division  in  Oscillatoria  to  the  union  of  two 
similar  masses  of  protoplasm  to  form  a  spore  in  Spirogyra, 
the  direct  fertilization  of  a  germ-cell  by  motile  anthero- 
zoids  in  Vaucheria,  Nitella,  Fucus,  the  indirect  fertilization 
of  fruiting  cells  by  non-motile  antherozoids  in  Nemalion. 
In  allies  of  the  latter  there  are  more  intricate  variations  of 
the  same  mode. 

The  algse  fall  into  five  natural  groups  based  primarily 
on  the  mode  of  fruiting.  In  most  cases  color  is  coordinate 
with  class  arid  may  be  relied  upon  as  a  superficial  guide  in 
grouping  ;  but  there  are  a  few  exceptions,  e.g.,  some  fruit- 
ing like  the  red  group  are,  nevertheless,  green. 

The  nutrition  of  the  brown  and  the  red  algae  is  similar 
to  that  of  the  green  algse,  since  the  brown  or  red  color 
merely  conceals  the  green  of  the  chlorophyll  which  is 
present  in  all  and  enables  them  all  to  take  in  and  decom- 
pose carbon  dioxide.1 

1  See  Murray's  Introduction  to  the  Study  of  Seaweeds,  pp.  4-6.  London, 
1895. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES     257 

305.  Classification  of  Types  studied. 

DIATOMACE^E.  Yellowish. 

Diatoms. 

CYANOPHYCE^E.  Blue-green  or  some  similar  color. 

Oscillatoria. 
CHLOROPHYCE.E.  Green. 

Pleurococcus,  Spirogyra, 

Vaucheria,  Nitella. 
PH.EOPHYCE.E.  Olive. 

Fucus. 
FLORIDE.E.  Red. 

Nemalion. 

Polysiphonia. 

THE  STUDY  OF  BLACK  MOULD  (RHIZOPUS  NIGRICANS) 

306.  Occurrence. — This  mould  maybe  found  in  abundance  on 
decaying  fruits,  such  as  tomatoes,  apples,  peaches,  grapes,  and  cher- 
ries, or  on  decaying  sweet  potatoes  or  squashes.     For  class  study  it 
may  most  conveniently  be  obtained  by  putting  pieces  of  wet  bread 
on  plates  for  a  few  days  under  bell-jars  and  leaving  in  a  warm  place 
until  patches  of  the  mould  begin  to  appear. 

307.  Examination   with  the  Magnifying  Glass Study  some  of 

the  larger  and  more  mature  patches  and  some  of  the  smaller  ones. 
Note  : 

(a)  The  slender,  thread-like  network  with  which  the  surface  of 
the  bread  is  covered.  The  threads  are  known  as  hyphce,  the  entire 
network  is  called  the  mycelium. 

(&)  The  delicate  threads  which  rise  at  intervals  from  the  myce- 
lium and  are  terminated  by  small  globular  objects.  These  little 
spheres  are  spore-cases.  Compare  some  of  the  spore-cases  with 
each  other  and  notice  what  change  of  color  marks  their  coming  to 
maturity. 

308.  Examination  with  the  Microscope.  —  Sketch  a  portion  of  the 
untouched  surface  of  the  mould  as  seen   (opaque)  with  a  two-inch 
objective,  then  compare  with  Fig.  189. 


258 


FOUNDATIONS   OF   BOTANY 


Wet  a  bit  of  the  mould,  first  with  alcohol,  then  with  water. 
Examine  in  water  with  the  half-inch  objective,  and  sketch  a  little  of 
the  mycelium,  some  of  the  spore-cases,  and  the  thread-like  stalks  on 
which  they  are  borne.  Are  these  stalks  and  the  mycelium  filaments 
solid  or  tubular  ?  Are  they  one-celled  or  several-celled  ? 

Mount  some  of  the  mature  spore-cases  in  water,  examine  them 
with  the  highest  obtainable  power,  and  sketch  the  escaping  spores. 


FIG.  189.  —  Unicellular  Mycelium  of  a  Mould  (Mucor  Mucedo),  sprung  from  a 
Single  Spore. 

a,  b,  and  c,  branches  for  the  production  of  spore-cases,  showing  various  stages  of 
maturity,    (Considerably  magnified.) 

Sow  some  of  these  spores  on  the  surface  of  "  hay-tea,"  made  by 
boiling  a  handful  of  hay  in  just  water  enough  to  cover  it  and  then 
straining  through  cloth  or  filtering  through  a  paper  filter.  After 
from  three  to  six  hours  examine  a  drop  from  the  surface  of  the 
liquid  with  a  medium  power  of  the  microscope  (half-inch  objective) 
to  see  how  the  development  of  hyphae  from  the  spores  begins. 
Sketch. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES 


259 


After  about  twenty-four  hours  examine  another  portion  of  the 
mould  from  the  surface  of  the  liquid  and  study  the  more  fully 
developed  mycelium.  Sketch. 

309.  Zygospores. — Besides 
the  spores  just  studied,  zy go- 
spores  are  formed  by  conju- 
gation of  the  hyphse  of  the 
black  moulds.  It  is  not  very 
easy  to  find  these  in  process 
of  formation,  but  the  student 
may  be  able  to  gather  from 
Fig.  190  the  nature  of  the 
process  by  which  they  are 
formed, — a  process  which  can- 
not fail  to  remind  him  of  the 
conjugation  of  pond-scum. 

THE  STUDY  OF  WHEAT 

RUST    (PUCCINIA 

GKAMTNB) 

310.  Occurrence.  —Wheat 
rust  is  common  on  cultivated 
wheat  and  other  grains,  and 
also  on  many  wild  and  culti- 
vated forage  grasses.  In  fact, 
this  or  similar  rusts  occur  on 
a  very  large  number  of  grasses, 
and  many  species  of  such  rusts 
are  recognked.  A  rust  may 
have  one,  two,  or  three  kinds 
of  spores,  and  when  three  occur  one  is  known  as  the  cluster-cup  stage 
and  the  others  as  red  rust  and  black  rust,  according  to  the  usual 
approximate  color  of  the  spores.  The  rust  called  Puccinia  graminis 
growing  on  wheat  has  its  cluster-cup  stage  on  the  leaves  of  barberry 
in  June.  The  spores  from  the  cluster-cups  are  carried  by  the  wind 
to  the  wheat,  where  they  germinate  and  in  a  few  days  produce  the 


FIG.  190.  —  Formation  of  Zygospores  in  a 

Mould  (Mucor  Mucedo). 
1,  threads  in  contact  previous  to  conjuga- 
tion ;  2,  cutting  off  of  the  conjugating 
cells,  a,  from  the  threads,  b ;  3,  a  later 
stage  of  the  process  ;  4,  ripe  zygospore  ;  5, 
germination  of  a  zygospore  and  formation 
of  a  spore-case.  (1-4  magnified  225  diam- 
eters, 5  magnified  about  60  diameters.) 


260 


FOUNDATIONS   OF   BOTANY 


red  rust.     A  little  later  the  black  spores  appear,  produced  from  the 
same  mycelium.     This  growth  is  chiefly  upon  the  stems  and  sheaths. 


-  0 


A  B 

FlG.  191.  —  Spore-Formation  in  Potato-Blight  (Phytophthora  infestans). 

A,  a  well-developed  group  of  stalks,  proceeding  from  a  mass  of  mycelium  inside 
the  leaf  and  escaping  through  a  stoma ;  B,  a  young,  unbranched  stalk,  h, 
hyphse  of  mycelium ;  o,  stoma ;  s,  spore.  (Both  figures  greatly  magnified,  B 
more  than  A.)  • 

311.  Cluster-Cup  Stage.  —  Note  with  the  naked  eye  and  with  a 
magnifying  glass  the  appearance  of  the  cluster-cups  upon  the  bar- 
berry leaf.  Fresh  specimens  should  be  used,  if  available.  Note 
whether  the  leaf  is  changed  in  form  or  color  in  any  part  occupied 
by  the  fungus.  Note  the  number  of  cups  in  a  cluster,  the  position 
on  the  leaf  (which  surface?),  the  form  and  size,  especially  the  height. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES     261 

Are  they  straight  or  curved  ?  Describe  the  margin  of  the  cup,  the 
color  without,  and  the  color  of  the  contents. 

With  a  power  of  200  diameters  or  more  examine  some  of  the 
cells  composing  the  cup  and  note  the  form,  color,  and  nature  of  the 
surface.  Draw.  With  the  point  of  a  needle  or  knife  pick  out  a 
bit  of  the  contents  of  the  cup  and  examine  as  above.  Note  the 
characters  as  before  and  compare  in  detail  with  the  cells  of  the  cup. 
The  cells  within  the  cup  are  the  spores.  Can  you  tell  how  they  are 
attached  ? 

A  thin  section  through  the  cup  will  show  the  mode  of  attachment 
and  the  relation  of  the  spores  to  the  cup. 

312.  Examination  of  Red  and  Black  Rust.  —  Under  the  magnify- 
ing glass  examine  the  eruptions  of  spores  (sort)  on  the  wheat  plant, 
some  of  red  spores  and  some  of  black  spores.  The  red  spores  are 
faded  in  dried  specimens.  .  Note  the  approximate  size  and  shape 
and  any  other  peculiarities.  Prepare  slides  of  each  kind  of  spores 
and  see  if  both  can  be  found  in  one  sorus.  The  spores  may  be 
taken  from  the  host-plant  on  the  point  of  a  knife  by  picking  rather 
deeply  down  into  the  sorus.  Place  the  small  quantity  of  spores  so 


FIG.  192.  —  A  Cluster-Cup  of  Anemone  Rust  (Puccinia  fusca).    (x  120.) 
s,  chains  of  spores  ;  p,  the  covering  or  peridium  of  the  cup  ;  /*,  hyphse. 

obtained  in  a  drop  of  water  on  a  slide,  spread  with  dissecting  needles 
and  cover.     Examine  under  a  power  of  200  or  more  diameters. 

The  red  spores  (uredospores)  have  each  a  stalk  from  which  they 
easily  fall.     They  may  be  seen  attached  to  their  stalks  if  properly 


262 


FOUNDATIONS   OF   BOTANY 


U 


prepared  cross-sections  through  the  sorus  are  available,  especially  if 
the  material  is  fresh.  Examine  the  spores  and  note  the  shape,  color, 
and  surface.  If  the  spores  are  shrunken,  a  drop  of  potash  solution 
will  restore  the  natural  plumpness.  Draw.  Spore-measurements  are 
important  in  determining  species.  The  uredospores  of  Puccinia 
graminis  may  be  distinguished  from  those  of  other  species  common 

on  grasses  by  the  greater  proportionate 
length. 

The  structure  of  the  black  spores 
(teleutospores)  can  be  made  out  with- 
out difficulty.  Some  should  be  found 
attached  at  the  base.  Note  the  parts 
and  the  differences  in  color  in  different 
portions.  Make  careful  drawings  to 
show  shape  and  structure  of  both  kinds 
of  spores. 

Boil  a  portion  of  a  rust-injured  plant 
in  potash  solution,  pick  it  to  pieces  011 
a  slide  under  the  magnifier  or  dissect- 
ing microscope,  use  a  cover-glass  and 
examine  the  preparation  for  mycelium, 
using  a  high  power. 

313.  Cultivation  on  a  Host-Plant.  — 
If  practicable,  find  some  wheat  or  grass 
which  has  remained  over  winter  with 
the  black  rust  upon  it.  Tie  a  bunch 
of  this  to  a  barberry  bush  while  the 
leaves  are  young  or  unexpanded.  When 
the  time  arrives  for  the  appearance  of 
the  cluster-cups,  note  whether  they  are  any  more  abundant  on  this 
bush  than  on  others.  Are  you  sure  that  the  rust  you  have  is  the 
one  to  which  the  barberry  cluster-cups  belong  ? 


FIG.  193.  — A  Group  of  Spores 
of  Wheat  Bust  (Puccinia 
graminis).     ( x  about  440.) 
ut  11,  uredospores  ;  t,  a  teleu- 
tospore. 


TYPES   OF   CKYPTOGAMS;   THALLOPHYTES  263 


THE    STUDY   OF   MICROSPH.ERA 

314.  Occurrence.  —  Species   of    Microsphcera    and    allied    forms 
occur  in  late  summer  and  fall  on  leaves  of  various  herbaceous  and 
woody  plants.     The  growth  is  confined  to  the  surfaces  of  the  leaf 
(upper,   lower,   or  both).     Among  the  most  available  species  are 
those  which  grow  upon  lilac,  oak,  grape,  cherry,  willow,  and  wild 
plants  of  the  sunflower  family.     Some  species  are  known  to  occur 
on  only  one  host-plant,  others  occur  on  several  or  a  large  number, 
and  the  host-plants  may  belong  to  one  or  more  than  one  family. 

Besides  MicrospJicera  there  are  about  five  other  genera,  any  of 
which  may  be  substituted  or  studied  comparatively.  They  are  dis- 
tinguished by  the  form  of  the  appendages,  together  with  the  number 
of  spore-sacs  (asci)  in  each  sac-receptacle  or  perithecium. 

The  species  of  fungi  which  Microsphcera  represents  are  called 
powdery  mildews. 

With  naked  eye  and  magnifying  glass  examine  the  surface  of  a 
leaf  bearing  powdery  mildew.  Note  which  surface  and  what  portion 
of  the  surface  is  occupied  by  the  fungus,  whether  the  occupied  area 
is  restricted  or  not,  the  color,  and  any  other  characters. 

315.  Examination  with  the  Microscope.  —  Place  a  small  drop  of 
water  on  the  leaf  where  the  fungus  occurs,  if  possible  where  dark- 
colored  specks  occur  among  the  mycelium.     Pick  from  the  leaf  a 
portion  of  the  fungus  loosened  by  the  water  and  place  with  a  drop 
of  water  on  a  slide.     Place  a  cover-glass  over  it.     Examine  under 
a  power  of  about  fifty  diameters.     The  dark-colored  specks  will  be 
seen  as  somewhat  spherical  bodies  (perithecia).     Note  their  structure 
and  color  and  their  appendages.     Have  the  perithecia  any  regular 
way  of  opening?     Note  the  length  of  the  appendages  as  compared 
with  the  diameter  of  the  perithecia ;  also  note  the  form  of  the  tips 
and  of  the  base,  the  color  and  any  variation  of  color  in  different 
parts  of  the  appendages.     Keep  the  left  hand  on  the  focusing  screw, 
and  with  the  needle  in  the  right  hand  press  with  gentle  but  varying 
stress  upon  the  cover-glass  to  rupture  the  perithecia.     Even  with 
great  care  broken  cover-glasses  may  result,  but  this  pressure  should 
force  out  the  contents  of  the  perithecia.      Another  method  is  to 
remove  the  slide  from  the  microscope  and,  with  a  pencil  rubber 


264 


FOUNDATIONS   OF   BOTANY 


applied  to  the  cover-glass,  rupture  the  perithecia  by  gentle  grinding 
between  the  cover  and  slide.  Note  the  number  and  form  of  the 
spore-sacs  (asci)  expelled  from  each  of  several  perithecia.  Examine 

under  a  power  of  about  200  diam- 
eters and  count  the  number  of  spores 
in  the  asci.  Gentle  pressure  may 
make  them  more  distinctly  visible. 
Make  drawings  to  illustrate  the 
structural  characters  observed. 


THE  STUDY  OF  AGARICUS 

316,  Occurrence.  —  The  common 
mushroom,  Agaricus  campestris, 
grows  in  open  fields  and  pastures 
in  the  United  States  and  Europe. 
It  is  the  mushroom  most  extensively 
cultivated  for   market,  and  if   not 
found  in  the  field  it  may  be  raised 
from  "  spawn "  (mycelium),  put  up 
in  the  shape  of  bricks,  and  sold  by 
seedsmen  in  the  large  cities.     Those 
who  make  a  specialty  of  selling  it 
furnish  directions  for  culture  free. 
A  moderately  warm  cellar  or  base- 
ment   makes    an    excellent   winter 
garden  for  mushrooms. 

317.  Structure    of    Mycelium. — 
Examine    some    of    the    spawn,    or 
mvcelium,  with  the  magnifying  glass 
and  the  low  power  of  the  microscope, 
and  with  a  power  of  200  diameters 
or    more    examine    the    individual 

hyphee  which  compose  it.  Are  the  hyphae  united  in  cord-like  strands 
or  otherwise,  or  are  they  entirely  separate  ?  Look  for  cross-partitions 
in  the  hyphae.  Is  there  any  peculiar  structure  to  be  found  at  these 
places  ?  Are  the  cross-partitions  near  together  or  widely  separated  ? 


FlG.  194. — A  Mushroom  (Agaricus 

melleus). 
my,   mycelium ;    c,   c',   c",   young 

"buttons"  ;  st,  stipe  or  stalk  ;  r, 

ring ;  g,  gills. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES 


265 


hym 


318,  The  Spore-Plant.  —  Search  for  indications  of  fruiting,  and 
note  the  appearance  of  the  "  button  mushrooms  "  in  all  available 
stages.    Draw.    See  if  at  any  stage  up  to  maturity  an  outer  envelope 
of  tissue  (volva)  can  be  found  enclosing  the  entire  fruiting  body. 
If  such  be  present,  what  becomes  of  it  at  maturity?     If  material  is 
available,  compare  the  species  of  Amanita  (poisonous)  in  regard  to  this. 

Examine  specimens  in  which  the  cap  is  expanding  and  see  if 
there  is  another  tissue  forming  a  veil  covering  the  under  surface  of 
the  cap.  If  such  be  pres- 
ent, how  is  it  attached 
and  what  becomes  of  it  ? 

Take  a  fresh,  well- 
expanded  mushroom  or 
toadstool.  Remove  the 
stalk,  or  stipe,  close  under 
the  cap,  or  pileus,  and  lay 
the  latter,  gills  down,  on 
a  piece  of  paper.  Let  it 
remain  undisturbed  for  a 
few  hours,  or  over  night, 
so  that  the  spores  may 
fall  upon  the  paper.  Note 
carefully  their  color,  also 
the  form  in  which  they 
are  arranged  on  the  paper.  What  determines  this  form  ?  Examine 
some  of  the  spores  under  the  highest  available  power  of  the  micro- 
scope. Measure  and  draw. 

Describe  the  stipe.  Is  it  a  hollow  tube  or  solid  ?  Does  it  taper  ? 
Note  length,  diameter,  color. 

Describe  the  cap,  or  pileus,  in  regard  to  diameter,  thickness,  nature 
and  color  of  the  upper  surface,  also  color  below. 

Examine  the  plates,  or  gills,  which  compose  the  under  portion  of 
the  pileus.  Cut  a  complete  pileus  and  stipe,  through  the  center,  and 
draw  an  outline  to  show  the  shape,  noting  particularly  how  the  gills 
are  attached.  What  is  the  color  of  the  gills  ? 

319.  Origin  of  Spores.  —  Make  a  cross-section  of  one  of  the  gills, 
and  with  a  magnifying  power  of  about  200  diameters  examine  the 


B 
FIG.  195.  —  Portions  of  Gills  of 

a  Fungus  (Agaricus). 
A,  slightly  magnified ;   B,  one 
of  the  parts  of  A,  more  mag- 
nified,    hym,  hymenium  ;    />, 
central  layer. 


266 


FOUNDATIONS   OF   BOTANY 


C 


fruiting  cells  (basidia)  which  project  at  right  angles  to  the  gill  and 
bear  the  spores.  At  how  many  points  (sterigmata)  on  each  basidium 
are  spores  attached  ?  Draw  a  basidium,  preferably  one  from  which 
the  spores  have  not  yet  fallen. 

THE  STUDY  OF  YEAST  (SACCHAROMYCES   CERE  VISILE) 

320.  Growth  of  Yeast  in  Dilute  Syrup.  —  Mix  about  an  eighth  of 
a  cake  of  compressed  yeast  with  about  a  teaspoonful  of  water  and 
stir  until  a  smooth,  thin  mixture  is  formed.  Add  this  to  about  half 

a  pint  of  water  in  which  a  table- 
spoonful  of  molasses  has  been 
dissolved.  Place  this  mixture  in 
a  wide-mouthed  bottle  which  holds 
one  or  one  and  a  half  pints,  stop- 
per very  loosely  1  and  set  aside  for 
from  twelve  to  twenty-four  hours 
in  a  place  in  which  the  temper- 
ature will  be  from  70  to  90  degrees. 
Watch  the  liquid  meantime  and 
note  : 

(a)  The  rise  of  bubbles  of  gas 
in  the  liquid. 

(6)  The  increasing  muddiness 
of  the  liquid,  a  considerable  sedi- 
ment usually  collecting  at  the  end 
of  the  time  mentioned. 

(c)  The  effect  of  cooling  off  the 
contents  of  the  bottle  by  immers- 
ing it  in  broken  ice  if  convenient, 
or,  if  this  is  not  practicable,  by 
standing  it  for  half  an  hour  in  a  pail  of  the  coldest  water  obtainable, 
or  leaving  it  for  an  hour  in  a  refrigerator,  afterwards  warming  the 
liquid  again. 

(d)  The  effect  of  shutting  out  light  from  the  contents  of  the 
bottle  by  covering  it  with  a  tight  box  or  large  tin  can. 

1  If  the  cork  is  crowded  into  the  neck  with  any  considerable  force,  pressure 
of  gas  and  an  explosion  may  result. 


S' 


FIG.  196.— Part  of  the  Preceding  Figure, 
(x  about  300.) 

(7,  layer  of  cells  immediately  under  the 
hymenium ;  s,  s',  s",  three  successive 
stages  in  growth  of  spores. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES     267 

(e)  The  result  of  filling  a  test-tube  or  a  very  small  bottle  with 
some  of  the  syrup-and-yeast  mixture,  from  which  gas-bubbles  are 
freely  rising,  and  immersing  the  small  bottle  up  to  the  top  of  the 
neck  for  fifteen  minutes  in  boiling  water.  Allow  this  bottle  to 
stand  in  a  warm  place  for  some  hours  after  the  exposure  to  hot 
water.  What  has  happened  to  the  yeast-plants? 

(/)  The  behavior  of  a  lighted  match  lowered  into  the  air  space 
above  the  liquid  in  the  large  bottle,  after  the  latter  has  been  standing 
undisturbed  in  a  warm  place  for  an  hour  or  more. 

(#)  The  smell  of  the  liquid  and  its  taste. 

321.  Microscopical  Examination  of  the  Sediment.1  —  Using  a  very 
slender  glass  tube  as  a  pipette,  take  up  a  drop  or  two  of  the  liquid 
and  the  upper  layer  of  the  sediment  and  place  on  a  glass  slide,  cover 
with  a  very  thin  cover-glass  and  examine  with  the  highest  power 
that  the  microscope  affords. 

Note: 

(a)  The  general  shape  of  the  cells. 

(&)  Their  granular  contents. 

(c)  The  clear  spot,  or  vacuole,  seen  in  many  of  the  cells. 

Sketch  some  of  the  groups  and  compare  the  sketches  with 
Fig.  197. 

Run  in  a  little  iodine  solution  under  one  edge  of  the  cover-glass, 
at  the  same  time  touching  a  bit  of  blotting  paper  to  the  opposite 
edge,  and  notice  the  color  of  the  stained  cells.  Do  they  contain  starch  ? 

Place  some  vigorously  growing  yeast  on  a  slide  under  a  cover- 
glass  and  run  in  a  little  eosiri  solution  or  magenta  solution.  Note 
the  proportion  of  cells  which  stain  at  first  and  the  time  required  for 
others  to  stain.  Repeat  with  yeast  which  has  been  placed  in  a  slen- 
der test-tube  and  held  for  two  or  three  minutes  in  a  cup  of  boiling 
water. 

With  a  very  small  cover-glass,  not  more  than  three-eighths  of  an 
inch  in  diameter,  it  may  be  found  possible  by  laying  a  few  bits  of 
blotting  paper  or  cardboard  on  the  cover-glass  and  pressing  it  against 
the  slide  to  burst  some  of  the  stained  cells  and  thus  show  their  thin, 
colorless  cell-walls  and  their  semi-fluid  contents,  protoplasm,  nearly 
colorless  in  its  natural  condition  but  now  stained  by  the  iodine. 
1  See  Huxley  and  Martin's  Biology,  under  Torula. 


268 


FOUNDATIONS   OF  BOTANY 


-b 


EXPERIMENT  XXXIX 

Can  Yeast  grow  in  Pure  Water  or  in  Pure  Syrup  ?  —  Put  a  bit  of 
compressed  yeast  of  about  the  size  of  a  grain  of  wheat  in  about  four 
fluid  ounces  of  distilled  water,  and  another  bit  of  about  the  same  size 
in  four  fluid  ounces  of  10  per  cent  solution  of  rock  candy  in  distilled 
water ;  place  both  preparations  in  a  warm  place,  allow  to  remain  for 
twenty-four  hours,  and  examine  for  evidence  of  the  growth  of  the 
yeast  added  to  each. 

322.  Size,  Form,  and  Structure  of  the  Yeast-Cell.  —  The  student 
has  discovered  by  his  own  observations  with  the  microscope  that  the 
yeast-cell  is  a  very  minute  object,  —  much  smaller  than  most  of  the 
vegetable  cells  which  he  has  hitherto  examined.     The  average  diam- 
eter of  a  yeast-cell  is  about  ^-$^-3 
of  an  inch,  but  they  vary  greatly 
both  ways  from  the  average  size. 

The  general  form  of  most  of 
the  cells  of  ordinary  yeast  is  some- 
what egg-shaped.  The  structure 
is  extremely  simple,  consisting  of 
a  thin  cell-wall,  which  is  wholly 
destitute  of  markings,  and  a  more 
or  less  granular  semi-fluid  proto- 
plasm, sometimes  containing  a 
portion  of  clearer  liquid,  the  vacu- 
ole,  well  shown  in  the  larger  cells 
of  Fig.  197.1 

323.  Substances  which  compose  the  Yeast-Cell.  —  The  cell- wall  is 
composed    mostly   of  cellulose;  the   protoplasm    consists  largely  of 
water,  together  with  considerable  portions  of  a  proteid  substance,2 

1  This  is  not  the  ordinary  commercial  yeast. 

2  It  may  be  found  troublesome  to  apply  tests  to  the  yeast-cell  on  the  slide, 
under  the  cover-glass.    Testing  a  yeast  cake  is  not  of  much  value,  unless  it 
may  be  assumed  that  compressed  yeast  contains  little  foreign  matter  and  con- 
sists mostly  of  yeast-cells.     Still  the  test  is  worth  making.     Millon's  reagent 
does  not  work  well,  but  the  red  or  maroon  color  which  constitutes  a  good  test 
for  proteids  is  readily  obtained  by  mixing  a  teaspoonful  of  granulated  sugar 
with  enough  strong  sulphuric  acid  to  barely  moisten  the  sugar  throughout, 
and  then,  as  quickly  as  possible,  mixing  a  bit  of  yeast  cake  with  the  acid  and 


FIG.  197. —  Yeast  (Saccharomyces  ellip- 
soideus)  budding  actively. 

A,  a  single  cell ;  B,  group  of  two  budding 
cells  ;  C,  a  large  group  ;  b,  buds. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES     269 

some  fat,  and  very  minute  portions  of  sulphur,  phosphorus,  potash, 
magnesia,  and  lime.  It  is  destitute  of  chlorophyll,  as  would  be 
inferred  from  its  lack  of  green  color,  and  contains  no  starch. 

324.  Food  of  the  Yeast-Cell ;  Fermentation.  —  The  diluted  molasses 
in  which  the  yeast  was  grown  in  Exp.  XXXIX  contained  all  the 
mineral  substances  mentioned  in  Sect.  323,  together  with  sugar, 
proteid  materials,  and  water.     The  addition  of  a  little  nitrate  of 
ammonium  would  probably  have  aided  the  growth  of  the  yeast  in 
this  experiment,  by  supplying  more   abundantly  the  elements  out 
of  which  the  yeast  constructs  its  proteid  cell-contents.     A  great  deal 
of  sugar  disappears  during  the  growth  of  the  yeast.1     Most  of  the 
sugar  destroyed  is  changed  into  carbon  dioxide  (which  the  student 
saw  rising  through  the  liquid  in  bubbles)  and  alcohol,  which  can 
be   separated   from    the    liquid   by   simple    means.      The    process 
of  breaking  up  weak    syrup   into   carbon  dioxide    and  alcohol  by 
aid  of  yeast  is  one  kind  of  fermentation;  it  is   of  great  practical 
importance,  in  bread-making  and  in  the  manufacture  of  alcohol. 
Since  grape  juice,  sweet  cider,   molasses   and  water,   and   similar 
liquids,  when  merely  exposed  to  the  air  soon  begin  to  ferment  and 
are  then  found  to  contain  growing  yeast,  it  is  concluded  that  dried 
yeast-cells,    in  the  form  of   dust,    must  be  everywhere  present  in 
ordinary  air. 

325.  Yeast  a  Plant;    a  Saprophyte.  —  The   yeast-cell   is   known 
to  be  a  plant,  and  not  an  animal,  from  the  fact  of  its  producing 
a  coating  of   cellulose  around  its  protoplasmic  contents  and  from 
the  fact  that  it  can  produce  proteids  out  of  substances  from  which 
animals  could  not  produce  them.2 

On  the  other  hand,  yeast  cannot  live  wholly  on  carbon  dioxide, 
nitrates,  water,  and  other  mineral  substances,  as  ordinary  green 
plants  can.  It  gives  off  no  oxygen,  but  only  carbonic  acid  gas,  and 
is  therefore  to  be  classed  with  the  saprophytes,  like  the  Indian  pipe, 
among  flowering  plants  (Sect.  180). 

sugar.  A  comparative  experiment  may  be  made  at  the  same  time  with  some 
other  familiar  proteid  substance,  e.g.,  wheat-germ  meal. 

1  The  sugar  contained  in  molasses  is  partly  cane  sugar  and  partly  grape 
sugar.    Only  the   latter  is  detected  by  the  addition  of  Fehling's  solution. 
Both  kinds  are  destroyed  during  the  process  of  fermentation. 

2  For  example,  tartrate  of  ammonia. 


270  FOUNDATIONS   OF   BOTANY 

326.  Multiplication  of  Yeast.  —  It  is  worth  while  to  notice  the 
fact  that  yeast  is  one  of  the  few  cryptogams  which  have  for  ages 
been  largely  cultivated  for  economic  purposes.     Very  recently  yeast 
producing  has  become  a  definite  art,  and  the  cakes  of  compressed 
yeast  so  commonly  sold  afford  only  one  instance   of  the   success 
that  has  been  attained  in  this  process.     While  yeast-cells  are  under 
favorable  conditions  for   growth,   they   multiply   with   very   great 
rapidity.     Little  protrusions   are  formed   at    some   portion  of  the 
cell-wall,  as  the  thumb  of  a  mitten  might  be  formed  by  a  gradual 
outgrowth  from  the  main  portion.     Soon  a  partition  of  cellulose 
is  constructed,  which  shuts  off  the  newly  formed  outgrowth,  making 
it  into  a  separate  cell,  and  this  in  turn  may  give  rise  to  others, 
while  meantime  the  original  cell  may  have  thrown  out  other  off- 
shoots.    The  whole  process  is  called  reproduction  by  budding.     It  is 
often  possible  to  trace  at  a  glance  the  history  of  a  group  of  cells, 
the  oldest  and  largest  cell  being  somewhere  near  the  middle  of  the 
group  and  the  youngest  and  smallest  members  being  situated  around 
the  outside.     Less  frequently  the  mode  of  reproduction  is  by  means 
of  spores,  new  cells  (usually  four  in  number),  formed  inside  one  of 
the  older  cells  (ascws).     At  length  the  old  cell-wall  bursts,  and  the 
spores  are  set  free,  to  begin  an  independent  existence  of  their  own. 

In  examining  the  yeast-cell  the  student  has  been  making  the 
acquaintance  of  plant  life  reduced  almost  to  its  lowest  terms.  The 
very  simplest  plants  consist,  like  the  slime  moulds,  of  a  speck  of 
jelly-like  protoplasm.  Yeast  is  more  complex,  from  the  fact  that  its 
protoplasm  is  surrounded  by  an  envelope  of  cellulose,  the  cell-wall. 

THE   STUDY   OF   PHYSCIA 

327.  Occurrence.  —  Physeia  is  one  of  the  commonest  lichens.     It 
grows  attached  to  the  bark  of  various  trees. 

328.  The  Thallus.  —  Physeia  consists  chiefly  of  an  irregularly 
expanded  growth  somewhat  leaf-like  in  texture.     It  is  best  to  be  wet 
for  study.     Is  it  separable  from  the  bark  to  which  it  is  attached  or 
is  it  combined  with  it  (incrusted)  ?    Describe  the  general  outline  of 
the  margin,  the  general  color,  and  any  special  variations  of  color 
above,  also  below.     How  is  the  thallus  attached  to  the  bark  ? 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES 


271 


329.  The  Fruit.  —  Look  for  small  lance-shaped  disks  seated  upon 
the  thallus.  Note  the  approximate  sizes  and  color  within  and 
without.  These  disks  are  called  apothecia.  Note  the  very  minute 
black  specks  (spermogones")  which  are  scattered  in  the  surface  of 
the  thallus.  Pick  one  from  the  thallus,  with  as  little  of  the  thallus 
as  possible,  and  examine  under  high  power.  It  may  be  macerated 
in  a  drop  of  potash  solution  and  crushed  under  the  cover-glass.  If 
the  contents  are  not  easily 
defined,  they  may  then  be 
made  more  opaque  by  a  drop 
of  acetic  acid  or  a  stain.  The 
minute  colorless  bodies  con- 
tained in  the  spermogones  are 


Fro.  198.  —  A  Lichen  (Xanthoria). 
(Natural  size.) 


FIG.  199.  — A  Lichen  (Usnea). 
(Natural  size.) 


called  spermatia.  Their  office  in  Physcia  is  obscure,  but  in  a  few 
lichens  they  are  thought  to  unite  with  a  trichogyne  cell,  as  in  the  red 
algse.1  Note  the  minute,  powdery  masses  (soredid)  on  the  surface 
of  the  thallus.  Macerate  if  necessary  under  the  cover-glass  and 
examine  under  a  high  power.  Compare  with  the  structure  of  the 
thallus  as  seen  in  cross-section.  (See  next  paragraph.)  These  soredia 
easily  become  detached  and  develop  into  new  plants. 

Prepare  for  sectioning  by  imbedding  a  small  portion  of  the 
thallus  with  an  apothecium  in  a  piece  of  pith  or  by  any  suitable 
device  for  sectioning,  and  cut  thin  sections  of  thallus  and  fruit. 

1  This,  however,  is  doubtful.  See  Strasburger,  Noll,  Schenk,  and 
Schimper's  Text-Book  of  Botany,  p.  380. 


272 


FOUNDATIONS   OF   BOTANY 


ff 


330.  Examination  of  the  Thallus.  —  The  thallus  of  Physcia  as  seen 
in  cross-section  will  be  found  to  consist  of  four  layers,  the  upper 
cortical,  gonidial,  medullary,  and  the  lower  cortical.  The  cortical 
layers  will  be  seen  to  serve  for  protection,  answering  the  purpose  of 
an  epidermis  or  bark.  The  cells  which  compose  them  make  what 
is  called  a  false  parenchyma,  —  resembling  parenchyma  in  form  but 

as  to  origin  being  trans- 

C  ^r^ll/Mrr^fZ^^    }Y*tf\    ^S/        formed  fungal  hyphae. 

Note  the  form  of  the 
hyphae  composing  the 
medullary  layer.     Are 
there    any   cross-parti- 
tions?    Do  any  cells 
appear  circular,  arid  if 
so,  what  is  the  explana- 
tion?    The  upper  por- 
tion  of  the  cortical 
layer,  having  green 
cells   intermixed,   con- 
stitutes the  gonidial 
layer.    Why  should  the 
green   cells   be  at  the 
upper  part  of  the  med- 
ullary layer?    Can  you 
detect  any  connection 
between  the  green  cells 
and  the  hyphae  ?      Do 
these    green    cells    re- 
semble  any  cells  pre- 
viously studied  ? 
Make  a  diagram  to  show  the  structure  of  the  thallus. 
What  arrangement  of  layers  would  you  expect  to  find  in  a  lichen 
thallus,  upright  or  suspended  ?     Compare  the  arrangement  in  the 
fruit-body  (apotkecium),  describe,  and  sketch.     How  does  the  layer 
of  cells  beneath  the  spore-sacs  resemble  the  cortical  layer  ?    All  but 
these  two  layers  may  be  considered  as  part  of  the  thallus.     To  make 
out  the  details  of  the  fruit,  the  section  must  be  very  thin. 


FIG.  200.  —  Transverse  Section  through  Thallus 
of  a  Lichen  (Sticta  fuliginosa) .    (x  500.) 

c,  cortical  or  epidermal  layer  ;  g,  gonidia  ;  /t,hyphse. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES     273 

Examine  the  spore-sacs  (asci)  and  look  for  spores  in  different  stages 
of  formation.  How  many  spores  are  found  in  each  ascus  ?  What  other 
bodies  occur  among  the  asci?  Draw  these,  also  asci  and  spores. 

331.  Lichens.  —  Lichens  were  formerly  supposed  to  be 
a  distinct  class  of  plants,  and  it  is  only  about  thirty  years 
since  their  real  nature  began  to  be  understood.  A  lichen 
is  now  known  to  be  a  combination  of  two  plants.  The 
green  cells,  called  the  gonidia,  belong  to  some  species  of 
alga,  and  the  remainder,  the  larger  portion  of  the  growth, 
is  a  fungus  parasitic  upon  that  alga.  The  groups  of 
lichens  correspond  in  structure  to  certain  groups  of  fungi, 
but  the  genera  are  sufficiently  distinct  so  that  lichens  are 
best  considered  by  themselves  for  purposes  of  study  and 
classification. 

The  relation  of  the  fungus  and  its  algal  host  is  not 
that  of  destructive  parasitism,  but  rather  a  mutual  rela- 
tion (symbiosis)  in  which  both  fungus  and  alga  may  have 
a  vigorous  growth.  The  relationship  has  been  investi- 
gated in  various  ways,  and  it  has  been  found  that,  while 
the  alga  may  grow  independent  of  the  fungus,  the  germi- 
nating fungus  spores  can  grow  only  to  a  limited  extent  if 
deprived  of  the  algal  host;  but  if  supplied  naturally  or 
artificially  with  the  proper  alga  they  make  a  normal 
growth. 

The  same  alga  may  serve  as  gonidia  to  a  number  of 
lichens,  often  of  very  different  form,  and  while  the  num- 
ber of  lichens  reaches  into  the  thousands,  the  number  of 
algse  known  to  serve  as  gonidia  is  quite  small. 

Lichens  are  widely  distributed  in  all  zones  but  flourish 
particularly  in  northern  regions  where  other  vegetation  is 
scanty.  Some  were  formerly  important  as  sources  of 


274  FOUNDATIONS  OF  BOTANY 

dyes.  "Iceland  moss"  is  a  lichen  used  for  food,  and  a 
finely  branching  form,  growing  in  extensive  mats  on  the 
soil,  serves  as  food  for  the  reindeer  and  is  known  as 
"  reindeer  moss." 

Most  lichens  grow  on  the  bark  of  trees,  on  rocks,  or  soil 
where  they  have  little  moisture  except  during  rainfall, 
but  some  grow  where  they  are  constantly  wet.  Some  of 
the  latter  are  gelatinous.  Most  of  the  conspicuous  lichens 
are  foliaceous  or  else  have  a  thallus  composed  of  branch- 
ing, cylindrical,  thread-like  portions.  But  many  species, 
often  less  conspicuous,  are  crustaceous,  growing  as  if 
they  formed  part  of  the  bark  or  rock  to  which  they  are 
attached. 

332.  Fungi.  —  The  yeasts,  moulds,  rusts,  mildews,  and 
mushrooms  represent  an  immense  group  of  plants  of  which 
about  forty-five  thousand  species  are  now  known  in  the 
world.  They  range  from  the  very  simple  to  quite  com- 
plex forms,  growing  as  saprophytes  or  parasites  under  a 
great  variety  of  conditions.  Their  structure  and  life 
history  are  so  varied  as  to  constitute  a  long  series  of  divi- 
sions and  subdivisions.1  Chlorophyll  is  absent  from  fungi, 
and  they  are  destitute  of  starch,  but  produce  a  kind  of 
cellulose  which  appears  to  differ  chemically  from  that  of 
other  plants.  Unable  to  build  up  their  tissues  from  car- 
bonic acid  gas,  water,  and  other  mineral  matters,  they  are 
to  be  classed,  with  animals,  as  consumers  rather  than  as 
producers,  acting  on  the  whole  to  diminish  rather  than  to 
increase  the  total  amount  of  organic  material  on  the  earth. 


1  See  Strasburger,  Noll,  Schenk,  and  Schimper's  Text-Book  of  Botany, 
pp.  340-381  incl.,  also  Potter  and  Warming's  Systematic  Botany,  p.  1,  and 
Engler's  Syllabus  der  Pflanzenfamilien,  Berlin,  1898,  pp.  25-47. 


TYPES  OF  CRYPTOGAMS;  THALLOPHYTES     275 

333.  Occurrence  and  Mode  of  Life  of  Fungi.  —  Among 
the  most  important  cryptogamous  plants  are  those  which, 
like  the  bacteria  of  consumption,  of  diphtheria,  of  typhoid 
fever,  or  of  cholera,  produce  disease  in  man  or  in  the 
lower  animals.  The  subclass  which  includes  these  plants 
is  known  by  the  name  Bacteria.  Bacteria  are  now  classed 
by  some  as  a  separate  group,  lower  than  fungi.  Some  of 
the  most  notable  characteristics  of  these  plants  are  their 
extreme  minuteness  and  their  extraordinary  power  of 
multiplication.  Many  bacteria  are  on  the  whole  highly 
useful  to  man,  as  is  the  case  with  those  which  produce 
decay  in  the  tissues  of  dead  plants  or  animals,  since  these 
substances  would,  if  it  were  not  for  the  destructive  action 
of  the  bacteria  of  putrefaction  and  fermentation,  remain 
indefinitely  after  death  to  cumber  the  earth  and  lock  up 
proteid  and  other  food  needed  by  new  organisms. 

The  mushrooms  and  their  allies  include  about  one-fourth 
of  the  fungi.  Some,  such  as  the  "  dry-rot "  fungus,  mis- 
takenly so  called,  cause  great  destruction  to  living  and 
dead  tree  trunks  and  timber  in  economic  use.  The  com- 
mon mushroom,  Agaricus  campestris,  is  the  most  important 
edible  species.  Probably  five  hundred  kinds  can  be  eaten, 
but  only  a  few  are  good  food,  and  even  these  contain  but  little 
nutriment.  Some  species  are  dangerous,  and  a  few  are  deadly 
poisons.  The  puffballs  are  a  small  group  allied  to  the  mush- 
rooms. Most  of  them  are  edible  and  of  good  quality. 

The  mildews  (Microsphcera,  etc.)  and  the  "black-knot" 
of  the  plum  trees  are  of  a  group  which  likewise  includes 
about  one-fourth  of  the  fungi.  A  considerable  number 
are  parasites,  injurious  to  vegetation,  while  thousands  of 
others  grow  on  dead  leaves,  twigs,  etc. 


276  FOUNDATIONS   OF  BOTANY 

The  "rust"  of  wheat  and  the  "smut"  of  corn  repre- 
sent groups  numbering  only  a  few  hundreds  of  species, 
which  are  very  important  because  they  are  all  parasites 
on  living  plants,  many  on  our  most  important  economic 
plants. 

Fig.  191,  representing  another  small  group  of  destruc- 
tive parasites,  shows  clearly  how  a  parasitic  fungus  grows 
from  a  spore  which  has  found  lodgment  in  the  tissues  of 
a  leaf  and  pushes  out  stalks  through  the  stomata  to  dis- 
tribute its  spores. 


mr 


CHAPTER   XXI 
TYPES   OF   CRYPTOGAMS;    BRYOPHYTES 

334,  The  Group  Bryophytes.  —  Under  this  head  are 
classed  the  liverworts  and  the  mosses.  Both  of  these 
classes  consist  of  plants  a  good  deal  more  highly  organized 
than  the  thallophytes. 
Bryophytes  have  no 
true  roots,  but  they 
have  organs  which 
perform  the  work  of 
roots.  Some  of  them 
have  leaves  (Fig.  206), 
while  others  have 
none  (Fig.  201). 
Fibro  -  vascular  bun- 
dles are  wanting.  The 
physiological  division 
of  labor  is  carried 
pretty  far  among  all 
the  bryophytes.  They 
have  special  appara- 
tus for  absorbing 
water  and  sometimes 
for  conducting  it 
through  the  stem;  stomata  are  often  present  and  some- 
times highly  developed.  There  are  chlorophyll  bodies, 
often  arranged  in  cells  extremely  well  situated  for  acting 

277 


FIG.  201.  —Part  of  Male  Thallus  of  a  Liverwort 

(Marchantia  disjuncta).    (Enlarged.) 

mr,  male  receptacle. 


278 


FOUNDATIONS   OF  BOTANY 


on  the  carbon  dioxide  gas  which  the  plant  absorbs,  that  is, 
arranged  about  rather  large  air  chambers. 

Reproduction  is  of  two  kinds,  sexual  and  asexual,  and 
the  organs  by  which  it  is  carried  on  are  complicated  and 
highly  organized.  An  alternation  of  generations  occurs, 
that  is,  the  life  history  of  any  species  embraces  two  forms : 
a  sexual  generation,  which  produces  two  kinds  of  cells  that 

by  their  union  give 
rise  to  a  new  plant ; 
the  asexual  genera- 
tion, which  multiplies 
freely  by  means  of 
special  cells  known 
as  spores. 


FIG.  202.  —Part  of  Female  Thallus  of 
M.  disjuncta.    (Enlarged.) 

fr,  female  receptacle  ;  c,  cups  with  gemmae. 


THE   STUDY  OF 
MARCHANTIA 


335.    Occurrence.— 

Marchantia  grows  on  soil 
or  rocks  in  damp  shaded  places  and  is  widely  distributed. 

336.  The  Thallus.  — In  general  form  the  thallus  bears  some  resem- 
blance to  that  of  some  of  the  lichens,  as  Parmelia,  but  is  plainly 
different  in  color,  mode  of  branching,  and  internal  structure  under 
the  microscope.  Under  the  microscope  (see  below)  the  individual 
cells  may  be  compared  with  those  of  the  medullary  layer  in  PJiyscia. 

Note  the  color  and  general  shape  of  the  thallus  and  study  care- 
fully the  mode  of  branching.  The  origin  of  the  growing  cells  is  at 
the  tip,  but  cells  so  originating  afterward  multiply  more  rapidly,  so 
that  the  tip  comes  to  be  in  a  notch. 

Viewing  the  thallus  as  an  opaque  object,  note  the  diamond-shaped 
network  on  the  upper  surface  and  the  dot-like  circle  in  the  middle 
of  each  diamond. 

Examine  the  under  surface  for  (1)  rhizoids  and  (2)  scales. 


TYPES   OF   CRYPTOGAMS;  BRYOPHYTES 


279 


idial  Receptacle  of   Marchantla. 
(Magnified.) 

a,  antheridium. 


337.  Internal  Structure. — Cut  thin  cross-sections  of  the  thallus 
in  the  same  way  as  for  Physcia,  making  some  pass  through  the  cir- 
cular dots  mentioned  above.     Exam- 
ine under  a  high  power  and  note  the 
different   kinds   and   layers   of   cells 
composing   the    thallus.       Note   the 
character   of   the   cells   forming  the 
upper  and  lower  surfaces.     Describe 
the  cells  which  are  next  above  those 
of  the  lower  epidermis,  their  shape, 
color  of  contents,  approximate  num- 
ber of  horizontal  rows.     Have  they 
any  evident  intercellular  spaces  ?  Find 

FIG.  203.  —  Section  through  Anther-    cells  connecting  these  with  the  upper 

epidermis  and  constituting  the  net- 
work of  lines  seen  on  the  surface  of 
the  thallus.  Note  the  air  cavity 

bounded  by  these  lines  and  the  loose  cells  which  occupy  it  in  part. 

What  is  the  color  of  their  contents  ?     How  are  they  attached,  and 

how  arranged?      Can  you   discover   any 

opening  through  the  epidermis?      If  so, 

describe  it. 

Make  drawings  to  illustrate  the  details 

of  structure  observed. 

338.  Gemmae.  —  Look   for    a   thallus 
bearing   little  green  cups  formed  of  its 
own   substance.      Describe   the   contents 
of  the  cup.     The  bodies  are  called  gemmce. 
They  originate  by  vegetative  growth  alone 
and  when  detached  may  grow  into  new 
plants. 

339.  Fruiting  Organs.  —  Look  for  thalli 
bearing  stalks  with  umbrella-like  expan- 
sions.    The  umbrellas  are  of  two  kinds, 
one   disk-like   with  crenate   points    (how 

many  ?)  and  the  other  has  rays  (how  many  ?)  elongated  and  curving 
downward.     Is  there  any  difference  in  the  height  of  the  two  kinds  ? 


az 


FIG.  204.  — Sectional  View  of 
an  Antheridium  of  Mar- 
chantia. 

a,  antheridium  ;  az,  anthero- 
zoids,  x  700. 


280 


FOUNDATIONS   OF   BOTANY 


Do  both  occur  on  the  same  thallus  ?     On  what  part  of  the  thallus 
do  they  occur,  and  do  they  differ  in  this  respect  ? 

340,  Antheridia.  —  The    antheridia    are    formed    as    outgrowths 
from  the  upper  surface  of  the  crenate  receptacle,  but  by  further 
growth  of  the  receptacle  they  become  imbedded.     They  should  be 
examined  under  a  high  power  and  sketched  in  outline.     The  anther- 
idium  produces  numerous  motile  antherozoids,  each  with  two  cilia. 

341,  Archegonia  and  Sporophytes.  —  The  receptacle  with  recurved 
rays  bears  the  archegonia.    Note  whether  they  occur  above  or  below 
and  in  what  relation  to  the  rays.    How  are  the  archegonia  protected  ? 

Note  the  cells  which  surround 
the  central  canal  and  form  the 
elongated  neck  of  the  archego- 
nium.  Does  the  archegonium 
open  upward  or  downward  ?  At 
the  base  look  for  the  germ-cell. 

The  antherozoids  enter  the 
central  canal  and  penetrating 
to  the  egg-cell  fertilize  it,  after 
which  it  begins  to  divide  and 
grows  into  a  sporophyte.  In  the 
older  specimens,  therefore,  the 
sporophytes  will  be  found  more 
or  less  developed.  The  archegonium  remains  upon  the  tip  of  the 
sporophytes.  The  mature  sporophyte  contains  the  spores  and  also 
peculiar  elongated  tapering  threads  with  spiral  thickenings.  These 
are  called  elaters. 

342,  Hepaticae.  —  Marchantia  represents   only  a  small 
division  of  the  Hepaticce,  and  is  not  typical  of  the  larger 
number  of  species.    In  spite  of  this  it  is  chosen  for  study, 
because  it  is  widely  distributed  and  more  available  for 
study  than  most  others.     In  most  species  the  fruit  lasts 
but  a  little  while  and  good  material  is  hard  to  obtain.     In 
Marchantia  the  fruiting  organs  are  abundant,  more  gradual 
in  their  development,  and  more  persistent.    Marchantia  and 


FIG.  205.  —  Sectional  View  of  Female 
Receptacle  of  Marchantia.    (x  5.) 


TYPES   OF   CRYPTOGAMS  ;   BRYOPHYTES  281 

its  allies  consist  chiefly  of  the  thallus  in  the  vegetative  con- 
dition, while  the  greater  number  of  Hepaticee  have  a  stem 
and  leaves.  Thus  they  approach  closely  to  the  mosses. 
But  mosses  usually  have  leaves  on  all  sides  of  the  stem, 
while  the  leaves  of  Hepaticse  are  two-ranked,  spreading 
laterally,  with  sometimes  a  third  row  of  leaves  or  scales 
underneath.  The  leaves  of  mosses  usually  have  more  than 
one  layer  of  cells  in  some  part,  but  the  leaves  of  the  leafy 
Hepaticse  have  but  one  layer  of  cells  throughout.  The 
forms  of  the  leaves  are  often  very  curious  and  interesting. 
The  sporophyte  of  most  mosses  consists  of  a  capsule  with 
a  lid,  while  in  the  leafy  Hepaticse  the  capsule  usually 
opens  by  splitting  longitudinally  into  two  to  four  valves. 

Different  species  of  Hepaticee  grow  on  damp  soil,  rocks, 
and  the  bark  of  trees.  Many  are  capable  of  enduring 
drought  and  reviving  with  moisture. 

THE   STUDY   OF   PIGEON-WHEAT   MOSS 
(P&LYTRICHUM   COMMUNE} 

343.  Occurrence.  —  This  moss  is  widely  distributed  over  the  sur- 
face of  the  earth,  and   some    of  its  relatives  are  among   the  best 
known    mosses    of    the  northern    United    States.      Here    it    grows 
commonly  in  dry  pastures  or   on  hillsides,  not  usually  in  densely 
shaded  situations. 

344.  Form,  Size,  and  General  Characters.  —  Study  several  speci- 
mens which  have  been  pulled  up  with  root-hairs.      Note  the  size, 
general  form,  color,  and  texture  of  all  the  parts  of  the  plants  exam- 
ined.    Some  of  them  probably  bear  spore-capsules  or  sporopkytes  like 
those  shown  in  Fig.  206,  while  others  are  without  them.    Sketch  one 
plant  of  each  kind,  about  natural  size. 

JVTiat  difference  is  noticeable  between  the  appearance  of  the 
leaves  in  those  plants  which  have  spore-capsules  and  those  which 
have  none  ?  Why  is  this  ? 


282 


FOUNDATIONS   OF   BOTANY 


In  some  specimens  the  stem  may  be  found,  at  a  height  of  an  inch 
or  more  above  the  roots,  to  bear  a  conical,  basket-shaped  enlargement, 


FIG.  206.  —A  Moss,  Catharinea. 

The  sporophytes  of  this  moss  are  usually  rather  more  slender  than  as 
here  represented. 


TYPES   OF   CRYPTOGAMS;   BRYOPHYTES 


283 


out  of  the  center  of  which  a  younger  portion  of  the  stem  seems  to 
proceed  ;  and  this  younger  portion  may  in  turn  end  in  a  similar 
enlargement,  from  which  a  still  younger  part  proceeds. 

Note  the  difference  in  general  appearance  between  the  leaves  of 
those  plants  which  have  just  been  removed  from  the  moist  collecting- 
box  and  those  which  have  been  lying  for  half  an  hour  on  the  table. 
Study  the  leaves  in  both  cases  with  the  magnifying  glass  in  order  to 
find  out  what  has  happened  to  them.  Of  what  use  to  the  plant  is 
this  change  ?  Put  some  of  the  partially  dried  leaves  in  water,  in  a 


prim 


FIG.  207.  —  Protonema  of  a  Moss. 


prim,  primary  shoot ;   h,  a  young  root-hair  ;  pi,  young  moss-plant ; 
br,  branches  of  primary  shoot. 

cell  on  a  microscope  slide,  cover,  place  under  the  lowest  power  of 
the  microscope,  and  examine  at  intervals  of  ten  or  fifteen  minutes. 
Finally  sketch  a  single  leaf. 

345.  Minute  Structure  of  the  Leaf  and  Stem.  —  The  cellular 
structure  of  the  pigeon-wheat  moss  is  not  nearly  as  simple  and  con- 
venient for  microscopical  study  as  is  that  of  the  smaller  mosses,  many 
of  which  have  leaves  composed,  over  a  large  part  of  their  surfaces, 
of  but  a  single  layer  of  cells,  as  shown  in  Fig.  209.  If  any  detailed 
study  of  the  structure  of  a  moss  is  to  be  made,  it  will,  therefore,  be 
better  for  the  student  to  provide  himself  with  specimens  of  almost 


284 


FOUNDATIONS   OF   BOTANY 


any  of  the  smaller  genera,1  and 
work  out  what  he  can  in  regard 
to  their  minute  anatomy. 


FIG.  208.  —  The  Antheridium 
of  a  Moss  (Funaria)  and  its 
Contents. 

a,  antheridium ;  6,  escaping 
antherozoids,  x  350  ;  c,  a  sin- 
gle antherozoid  of  another 
moss,  x  800. 


e  *s 


I  J 


FIG.  209.  — Portions  of  Fertile  Plant 
of  a  Moss  (Funaria). 

A,  longitudinal  section  of  summit  of 
plant,  x  100 ;  a,  archegonia ;  I, 
leaves  ;  E,  an  archegonium,  x  550  ; 
e,  enlarged  ventral  portion  with 
central  cell ;  n,  neck  ;  TO,  mouth. 


346.  Sporophytes.  —  That  part  of  the  reproductive  apparatus  of 
a  common  moss  which  is  most  apparent  at  a  glance  is  the  sporophyte 
or  spore-capsule  (Fig.  206).  This  is  covered,  until  it  reaches  maturity, 
with  a  hood  which  is  easily  detached.  Remove  the  hood  from  one 

1  As  Mniwn  or  Bryum. 


TYPES   OF   CRYPTOGAMS;   BRYOPHYTES  285 

of  the  capsules,  examine  with  a  magnifying  glass,  and  sketch  it. 
Note  the  character  of  the  material  of  which  its  outer  layer  is 
composed. 

Sketch  the  uncovered  capsule  as  seen  through  the  magnifying 
glass,  noting  the  little  knob  at  its  base  and  the  circular  lid. 

Pry  off  this  lid,  remove  some  of  the  mass  of  spores  from  the 
interior  of  the  capsule,  observe  their  color  as  seen  in  bulk  through 
the  magnifying  glass,  then  mount  in  water,  examine  with  the  high- 
est obtainable  power  of  the  microscope,  and  sketch  them.  These 
spores,  if  sown  on  moist  earth,  will  each  develop  into  a  slender, 
branched  organism,  consisting,  like  pond-scum,  of  single  rows  of 
cells  (Fig.  207)  called  the  protonema. 

347.  Other  Reproductive  Apparatus.  —  The  student  cannot,  with- 
out spending  a  good  deal  of  time  and  making  himself  expert  in  the 
examination  of  mosses,  trace  out  for  himself  the  whole  story  of  the 
reproduction  of  any  moss.  It  is  sufficient  here  to  give  an  outline  of 
the  process.  The  protonema  develops  buds,  one  of  which  is  shown 
in  Fig.  207,  and  the  bud  grows  into  an  ordinary  moss  plant.  This 
plant,  in  the  case  of  the  pigeon-wheat  moss,  bears  organs  of  a  some- 
what flower-like  nature,  which  contain  either  antheridia  (Fig.  208), 
organs  which  produce  fertilizing  cells  called  antherozoids,  or  arcTie- 
gonia  (Fig.  209),  organs  which  produce  egg-cells,  but  in  this  moss 
antheridia  and  archegonia  are  not  produced  in  the  same  "moss- 
flower."  The  plants  therefore  correspond  to  dioecious  ones  among 
flowering  plants. 

After  the  fertilization  of  the  egg-cell,  by  the  penetration  of 
antherozoids  to  the  bottom  of  the  flask-shaped  archegonium,  the 
development  of  the  egg-cell  into  sporophyte  begins  ;  the  latter  rises 
as  a  slender  stalk,  while  the  upper  part  of  the  archegonium  is 
carried  with  it  and  persists  for  a  time  as  the  hood  or  calyptra. 


CHAPTER   XXII 
TYPES   OF   CRYPTOGAMS;    PTERIDOPHYTES 

348.  The  Group  Pteridophytes.  —  Under  this  head   are 
classed  the  ferns,  the  scouring-rushes,  and  the  club-mosses. 
They  are  the  most  highly  organized  of  cryptogams,  having 
true  roots,  and  often  well-developed  stems  and  leaves. 

THE   STUDY   OF   A   FERN* 

349.  Conditions  of  Growth.  —  If  the  specimens  studied  were  col- 
lected by  the  class,  the  collectors  should  report  exactly  in  regard  to 
the  soil  and  exposure  in  which  the  plants  were  found  growing.     Do 
any  ferns  occur  in  surroundings  decidedly  different  from  these? 
What  kind  of  treatment  do  ferns  need  in  house  culture? 

350.  The  Underground  Portion.  —  Dig  up  the  entire  underground 
portion  of   a  plant  of  ladyfern.     Note  the  color,  size,  shape,  and 
appendages  of  the  rootstock.     If  any  are  at  hand  which  were  col- 
lected in  their  late  winter  or  early  spring  condition,  examine  into 
the  way  in  which  the  leafy  parts  of  the  coming  season  originate 
from  the  rootstock,  and  note  their  peculiar  shape  (Fig.  210,  A). 
This  kind  of  vernation  (Sect.  136)  is  decidedly  characteristic  of  ferns. 
Observe  the  number  and  distribution  of  the  roots  along  the  rootstock. 
Bring  out  all  these  points  in  a  sketch. 

1  The  outline  here  given  applies  exactly  only  to  Asplenium  filix-fcemina. 
Any  species  of  Asplenium  or  of  Aspidium  is  just  as  well  adapted  for  study. 
Cystopteris  is  excellent,  but  the  indusium  is  hard  to  find.  Polypodium  vut- 
gare  is  a  simple  and  generally  accessible  form,  but  has  no  indusiuin.  Pteris 
aquilina  is  of  world-wide  distribution,  but  differs  in  habit  from  most  of  our 
ferns.  The  teacher  who  wishes  to  go  into  detail  in  regard  to  the  gross  anat- 
omy or  the  histology  of  ferns  as  exemplified  in  Pteris  will  find  a  careful  study 
of  it  in  Huxley  and  Martin's  Biology,  or  a  fully  illustrated  account  in  Sedg- 
wick  and  Wilson's  Biology. 

286 


TYPES   OF   CRYPTOGAMS;   PTERIDOPHYTES          287 

351.  The  Frond.  —  Fern  leaves  are  technically  known  as  fronds. 
Observe  how  these  arise  directly  from  the  rootstock. 

Make  a  somewhat  reduced  drawing  of  the  entire  frond,  which 
consists  of  a  slender  axis,  the  rhachis,  along  which  are  distributed 
many  leaflets  or  pinnce,  each  composed  of  many  pinnules.  Draw  the 
under  side  of  one  of  the  pinnae,  from  near  the  middle  of  the  frond, 
enlarged  to  two  or  three  times  its  natural  size,  as  seen  through  the 
magnifying  glass.  Note  just  how  each  pinnule  is  attached  to  its 
secondary  rhachis. 

Examine  the  under  side  of  one  of  the  pinnules  (viewed  as  an 
opaque  object  without  cover-glass)  with  the  lowest  power  of  the 
microscope,  and  note : 

(a)  The  "  fruit-dots  "  or  sori  (Fig.  210,  B)  (already  seen  with  the 
magnifying  glass,  but  now  much  more  clearly  shown). 

(&)  The  membranous  covering  or  indusium  of  each  sorus  (Fig. 
210,  C).  Observe  how  this  is  attached  to  the  veins  of  the  pinnule. 
In  such  ferns  as  the  common  brake  (Pteris}  and  the  maidenhair 
(Adianturri)  there  is  no  separate  indusium,  but  the  sporangia  are 
covered  by  the  incurved  edges  of  the  fronds. 

(c)  The  coiled  spore-cases  or  sporangia,  lying  partly  covered  by 
the  indusium.  How  do  these  sporangia  discharge  their  spores  ? 

Make  a  drawing,  or  several  drawings,  to  bring  out  all  these  points. 

Examine  some  of  the  sporangia,  dry,  with  a  power  of  about  fifty 
or  seventy-five  diameters,  and  sketch.  Scrape  off  a  few  sporangia, 
thus  disengaging  some  spores,  mount  the  latter  in  water,  examine 
with  a  power  of  about  200  diameters,  and  draw. 

352.  Life  History  of  the  Fern.  —  When  a  fern-spore  is  sown  on 
damp  earth  it  gradually  develops  into   a  minute,  flattish   object, 
called  a  prothallium  (Fig.  211).     It  is  a  rather  tedious  process  to 
grow  prothallia  from  spores,  and  the  easiest  way  to  get  them  for 
study  is  to  look  for  them  on  the  earth  or  on  the  damp  outer  surface 
of  the  flower-pots  in  which  ferns  are  growing  in  a  greenhouse.     All 
stages  of  germination  may  readily  be  found  in  such  localities. 

Any  prothallia  thus  obtained  for  study  may  be  freed  from  par- 
ticles of  earth  by  being  washed,  while  held  in  very  small  forceps,  in 
a  gentle  stream  of  water  from  a  wash-bottle.  The  student  should 
then  mount  the  prothallium,  bottom  up,  in  water  in  a  shallow  cell, 


288 


FOUNDATIONS   OF  BOTANY 


FIG.  210.  —  Spore-Plant  of  a  Fern  (Aspidium  Filix-mas). 

A,  part  of  rootstock  and  fronds,  not  quite  one-sixth  natural  size  ;  fr,  young  fronds 
unrolling ;  J3,  under  side  of  a  pinnule,  showing  sori,  s  ;  C,  section  through  a 
sorus  at  right  angles  to  surface  of  leaf,  showing  indusium,  i,  and  sporangia,  s  ; 
.D,  a  sporangium  discharging  spores.  (B  is  not  far  from  natural  size.  C  and 
D  are  considerably  magnified.) 


TYPES   OF   CRYPTOGAMS;   PTERIDOPHYTES 


289 


cover  with  a  large  cover-glass,  and  examine  with  the  lowest  power 
of  the  microscope.     Note  : 

(a)  The  abundant  root-hairs,  springing  from  the  lov»T3r  surface 
of  the  prothallium. 

(&)  The  variable  thickness  of  the  prothallium,  near  the  edge, 
consisting  of  only  one  layer  of  cells. 

(c)  (In  some  mature  specimens)  the  young  fern  growing  from 
the  prothallium,  as  shown  in  Fig.  211,  B. 

The  student  can  hardly  make  out  for  himself,  without  much 
expenditure  of  time,  the  structure  of  the  antheridia  and  the  arclie- 
gonia  (Fig.  211,  ,4), 
by  the  cooperation 
of  which  fertilization 
takes  place  on  much 
the  same  plan  as  that 
already  described  in 
the  case  of  mosses. 
The  fertilized  egg- 
cell  of  the  archego- 
nium  gives  rise  to 
the  young  fern,  the 
sporophyte  which 
grows  at  first  at  the 
expense  of  the  parent 
prothallium  but  soon 
develops  roots  of  its 
own  and  leads  an  in- 
dependent existence. 

353.  Nutrition.— 
The  mature  fern 
makes  its  living,  as  flowering  plants  do,  by  absorption  of  nutritive 
matter  from  the  soil  and  from  the  air,  and  its  abundant  chlorophyll 
makes  it  easy  for  the  plant  to  decompose  the  supplies  of  carbon 
dioxide  which  it  takes  in  through  its  stomata. 


FIG.  211.  — Two  Prothallia  of  a  Fern  (Aspidium). 
A,  under  surface  of  a  young  prothallium  ;  ar,  arche- 
gonia ;  an,  antheridia ;  r,  rhizoids  ;  B,  an  older  pro- 
thallium  with  a  young  fern-plant  growing  from  it ; 
I,  leaf  of  young  fern.     (Both  x  about  8.) 


290  FOUNDATIONS  OF  BOTANY 


FERNS 

354.  Structure,  Form,  and  Habits  of  Ferns. —  The  struc- 
ture of  ferns  is  much  more  complex  than  that  of  any  of 
the  groups  of  cryptogamous  plants  discussed  in  the  earlier 
portions  of  the  present  chapter.     They  are  possessed  of 
well-defined  nbro-vascular  bundles,  they  form  a  variety  of 
parenchymatous  cells,  the  leaves  have  a  distinct  epidermis 
and  are  provided  with  stomata. 

Great  differences  in  size,  form,  and  habit  of  growth  are 
found  among  the  various  genera  of  ferns.  The  tree  ferns 
of  South  America  and  of  many  of  the  islands  of  the  Pacific 
Ocean  sometimes  rise  to  a  height  of  forty  feet,  while  the 
most  minute  species  of  temperate  and  colder  climates  are  not 
as  large  as  the  largest  mosses.  Some  species  climb  freely, 
but  most  kinds  are  non-climbing  plants  of  moderate  size, 
with  well-developed  rootstocks,  which  are  often,  as  in  the 
case  of  the  bracken-fern,  or  brake,1  and  in  Osmunda,  very 
large  in  proportion  to  the  parts  of  the  plant  visible  above 
ground. 

355.  Economic  Value  of  Ferns.  —  Ferns  of  living  species 
have  little  economic  value,  but  are  of  great  interest,  even 
to  non-botanical  people,  from  the  beauty  of  their  foliage. 

During  that  vast  portion  of  early  time  known  to  geolo- 
gists as  the  Carboniferous  Age,  the  earth's  surface  in  many 
parts  must  have  been  clothed  with  a  growth  of  ferns  more 
dense  than  is  now  anywhere  found.  These  ferns,  with 
other  flowerless  herbs  and  tree-like  plants,  produced  the 
vegetable  matter  out  of  which  all  the  principal  coal  beds 
of  the  earth  have  been  formed. 

1  Pteris  aquilina. 


TYPES   OF   CRYPTOGAMS;   PTERIDOPHYTES          291 

356.  Reproduction  in  Ferns. — The  reproduction  of  ferns 
is  a  more  interesting   illustration  of  alternation  of  gen- 
erations than  is  afforded  by  mosses.      The  sexual  plant, 
gametophyte,    is   the    minute    prothallium,   and   the    non- 
sexual  plant,  sporophyte,   which  we    commonly   call   the 
fern,  is  merely  an  outgrowth  from  the  fertilized  egg-cell, 
and  physiologically  no  more  important  than  the  sporophyte 
of  a  moss,  except  that  it  supplies  its  own  food  instead  of 
living  parasitically.     Like  this  sporophyte,  the  fern  is  an 
organism  for  the  production  of   vegetative  spores,  from 
which  new  plants  endowed  with  reproductive  apparatus 
may  grow. 

THE   STUDY   OF   A   CLUB-MOSS    (LYCOPODIUM} 

357.  Occurrence.  —  Several  species  of  Lycopodium  are  common  in 
rich  woods  in  the  northern  and  mountainous  portions  of  the  eastern 
United  States.     Any  species  may  be  studied. 

358.  Examination.  —  Note  whether  the  plant  is  chiefly  erect  or 
prostrate  and  vine-like.     Describe  the  mode  of  branching.     Are  the 
leaves  arranged  flat-wise  or  equally  on  all  sides  of  the  stem  ?   Describe 
the  leaves  briefly.     Are  they  all  of  one  kind  or  do  some  portions  of 
the  plant  evidently  have  smaller  leaves? 

Select  fruiting  specimens  and  determine  the  position  of  the  spo- 
rangia. Is  the  leaf,  near  whose  base  each  sporangium  is  situated,  like 
the  ordinary  foliage  leaves  of  the  plant  ?  Are  the  fruiting  portions 
of  the  plant  similar  in  general  aspect  or  different  from  the  rest  of 
the  plant  and  raised  above  it  on  stalks  ?  Examine  the  spores.  Are 
they  all  of  one  kind  ? 

If  Selaginella  is  used  in  place  of  Lycopodium  or  for  comparison, 
two  kinds  of  sporangia  are  to  be  sought,  differing  chiefly  in  shape. 
Describe  each  briefly.  Compare  the  number  of  spores  in  each.  The 
larger  spores  (macrospores)  germinate  and  at  length  produce  pro- 
thallia  bearing  archegonia,  while  the  smaller  produce  prothallia 
bearing  antheridia.  The  archegonia,  after  fertilization,  develop  each 


292 


FOUNDATIONS   OF  BOTANY 


an  embryo.     This  grows,  remaining   for   a  time  attached  to  the 
macrospore,  and  at  length  forms  a  new  spore-plant. 


THE   STUDY   OF   A   SCOUBING-RUSH  (EQUISETUM} 

359,  Occurrence.  —  The  common  horse-tail,  Equisetum  arvense,  is 
widely  distributed  in  the  United  States,  east,  west,  north,  and  south. 
It  is  very  often  found  on  sand  hills  and  along  railroad  embankments. 


FIG.  212.  —  Plant  of  Lycopodium  (L.  annotinum). 

The  fruiting  stems  appear  very  early  in  the  spring  and  are  of  short 
duration.  The  sterile  vegetative  growth  follows,  becoming  well 
grown  in  June. 

360.  Examination  of  Rootstocks  and  Roots.  —  Examine  the  under- 
ground portions  of  the  plant  with  reference  to  general  size,  position, 
color,  shape,  and  position  of  notches.  After  studying  the  stems 


TYPES   OF   CRYPTOGAMS;   PTEKIDOPHYTES          29$ 


above  ground  insert  here  any  evident  points  of  comparison.  Do  you 
find  any  special  forms  of  stem  development  suited  to  a  special  pur- 
pose ?  Are  there  any  organs  in  the  nature  of  leaves  ? 


FIG.  213.— A  Scouring-Kush  (Equisetum  sylvaticum) .  At  the  right  is  a 
colorless  fertile  stem,  in  the  middle  a  green  sterile  one,  and  at  the 
left  a  green  fertile  one. 


294  FOUNDATIONS  OF  BOTANY 

361.  Sterile  Stems.  —  Examine    the   stems  above   ground  with 
reference  to  their  color  and  mode  and  degree  of  branching.     What 
is  the  character  of  the  leaves  ?     Do  the  stems  in  any  sense  serve  as 
leaves?     Observe  the  nodes  composing  the  stem  and  note  the  posi- 
tion of  the  leaves  on  the  stems.     Do  they  appear  to  be  placed  several 
at  the  same  level  (whorled)  ? 

Examine  with  a  magnifying  glass  the  surface  of  the  stem  and 
note  the  number  of  ridges  and  grooves.  Compare  the  number  and 
position  of  the  leaves  with  reference  to  these. 

362.  Mineral  Matter  in  Stem.  —  Treat  small  pieces  of  the  stem 
with  strong  nitric  acid  to  remove  all  vegetable  substance  and  note 
the  mineral  substance  remaining.     Treat  in  a  similar  way  thin  cross- 
sections  and  examine  under  the   microscope.      The   substance    is 
silica.     It  gives  the  plant  its  gritty  feeling  and  its  name  and  use  as 
"  scouring-rush."     Of  what  use  is  it  to  the  plant?     Use  of  the  same 
substance  in  outer  rind  of  corn  stem,  bamboo  stem,  and  straw  of 
grains  ? 

363.  Microscopic  Examination.  —  Make  thin  cross-sections  of  the 
stem  and  examine  under  the  lowest  power  of  the  microscope.     Make 
a  diagrammatic  sketch  to  indicate  the  central  cavity,  the  number 
and  position  of  the  nbro-vascular  bundles,  the  cavity  or  canal  in 
each,  the  ring  of  tissue  surrounding  the  ring  of  bundles,  and  the 
larger  cavities  or  canals  outside  of  this.     Where  is  the  chlorophyll 
located?     Can  stomata  be  found,  and  if  so,  what  is  their  location 
and  arrangement? 

364.  Fertile  Stems.  — Describe  the  fruiting  stem  with  reference  to 
general  aspect,  size,  color,  number,  and  length  of  internodes,  position 
of  spore-bearing  portion,  color  of  spores  in  mass.     Note  the  shield- 
shaped  bodies    (transformed  leaves  or   sporophylls}   composing  the 
cone-like  "flower"  and  see  whether  any  joints  can  be  detected  where 
they  are  attached.     Examine  the  inner   surface  of  the  shields  for 
sporangia  and  spores.     Examine  the  sporangia  under  a  low  power 
of  the  microscope.      Examine  some  spores  under  a  higher  power. 
Note  the  two  bands,  elaters,  on  each  spore,  crossing  each  other  and 
attached  only  at  the  point  of  crossing,  forming  four  loose  appendages. 
Watch  these  while  some  one  moistens  them  by  gently  breathing 
upon  them  as  they  lie  uncovered  on  the  slide  under  the  microscope 


TYPES   OF   CRYPTOGAMS;   PTERIDOPHYTES 


295 


and  note  the  effect.     Also  note  the  effect  of  drying.     How  does  this 
affect  the  spores  ?     Use  of  the  bands  ? 

365.  Germination  of  Spores.  —  The  spores  germinate  while  fresh 
and  form  prothallia  corresponding  to  those  of  ferns,  but  generally 
dioecious.     The   prothallium  which   bears  the  antheridia   remains 
comparatively  small,  and  the  antheridia  are  somewhat  sunken.     The 
others  grow  much  larger  and  branch  profusely. 

The  terminal  portion  becomes  erect  and  ruffled. 
Near  this  part  the  archegonia  are  formed,  quite 
similar  to  those  of  ferns.  The  embryo  plant 
developing  from  the  germ-cell  has  its  first  leaves 
in  a  whorl.  This  at  length  grows  into  a  spore- 
plant  like  that  shown  in  Fig.  213. 

About  twenty-five  species  of  Equisetum  are 
known.  Several  may  be  looked  for  in  any 
locality  and  may  well  be  compared  with  the  one 
described  above,  in  regard  to  form,  mode  of 
branching,  and  mode  of  fruiting. 

366,  Fern-Plants     (Pteridophytes).  - 

The  Pteridophytes  (literally  fern-plants) 
include  in  their  general  category  not  only 
ferns  as  commonly  recognized,  but  several 
other  small  groups  which  are  very  inter- 
esting on  account  of  their  diversity.  All 
cryptogams  higher  than  mosses  belong  in 
this  group.  In  moss  plants  the  individ- 
uals growing  from  spores  and  bearing 
antheridia  and  archegonia,  the  gameto- 
phytes,  are  full-grown  leafy  plants,  and 
the  spore-bearing  plant,  or  sporophyte,  is 
merely  a  stalk  bearing  a  sporangium.  In 
all  the  fern-plants  the  reverse  is  true. 
The  individuals  growing  from  spores  and 

,          .  ,        .  ,.  ,  .  a,  mouth  of  a  ferti- 

bearing  antheridia  and  archegonia  are  of     iized  arcnegomum. 


FIG.  214.  — Part  of  a 
Lobe  of  the  Mature 
Female  Prothal- 
lium of  Equisetum. 
(x  about  50.) 


296  FOUNDATIONS   OF   BOTANY 

minor  vegetative  development  (prothalUa),  while  the  spore- 
bearing  plant  is  a  leafy  plant,  even  a  tree  in  some  ferns. 

The  ferns  in  the  strictest  sense  have  sporangia  derived 
from  the  epidermis  (transformed  hairs),  while  a  few  plants 
closely  resembling  them  in  general  aspect  (Botrychium,  etc.) 
have  sporangia  formed  in  the  tissue  of  the  leaf. 

In  the  next  subdivision,  the  water-ferns  (Fig.  215),  there 
is  little  resemblance  to  the  common  ferns.  The  sporangia 
are  in  special  receptacles  at  the  basal  portion  of  the  plant. 
The  spores  are  of  two  kinds,  dioecious,  one  on  germination, 
producing  antheridia,  the  other  archegonia.  This  group 
includes  two  rooting  forms,  Marsilea  (with  leaves  resem- 
bling a  four-leaved  clover)  and  Pilularia,  bearing  simple 
linear  leaves,  and  two  floating  forms,  Salvinia  (Fig.  215) 
and  Azolla. 

The  remaining  groups  of  fern-plants  are  the  horse-tails 
and  the  club-mosses.  The  horse-tails  have  only  one  kind 
of  spore  and  are  peculiar  chiefly  in  their  vegetative  aspect 
(Fig.  213),  while  the  spore-bearing  leaves,  or  sporophylls, 
are  arranged  in  the  form  of  a  cone,  as  already  shown. 

The  club-mosses  include  some  plants  which,  as  their 
name  implies,  have  a  superficial  resemblance  to  a  large 
moss,  with  the  addition  of  a  club-shaped  stalked  fruiting 
spike.  These  are  the  so-called  "ground  pines"  and  the 
running  ground  "  evergreens  "  used  for  Christmas  festoons 
in  New  England.  Technically  the  group  is  distinguished 
by  the  possession  of  firm-walled  sporangia  formed  singly 
near  the  bases  of  the  leaves.  The  ordinary  club-mosses 
already  referred  to  have  but  one  kind  of  spore,  while 
plants  called  Selaginella  and  Isoetes  have  two  kinds  of 
spores,  in  this  respect  resembling  Marsilea.  In  many 


TYPES   OF   CRYPTOGAMS;   PTERIDOPHYTES          297 

species  of  Selaginella  the  leaves  are  arranged  flat-wise  on 
the  stem,  so  that  considered  physiologically  the  branch- 
ing stem  and  its  leaves  together  serve  as  a  foliage  leaf. 
In  one  of  the  commonest  American  forms,  however,  the 
stem  is  more  nearly  erect,  and  the  leaves  are  all  alike  and 
four-ranked. 

Isoetes  (quill-wort)  grows  attached  to  the  soil  in  shallow 
water  at  the  bottoms  of  ponds.  It  has  the  aspect  of  short 
grass  growing  in  bunches.  The  large  sporangia  are  at  the 
broad  bases  of  the  leaves. 

367.  High  Organization  of  Pteridophytes.  —  The  student 
may  have  noticed  that  in  the  scouring-rush  and  the  club- 
moss  studied  there  are  groups  of  leaves  greatly  modified 
for  the  purpose  of  bearing  the  sporangia.  These  groups 
are  more  nearly  equivalent  to  flowers  than  anything  found 
in  the  lower  spore-plants,  and  the  fern-plants  which  show 
such  structures  deserve  to  be  ranked  just  below  seed-plants 
in  any  natural  system  of  classification. 

The  variety  of  tissues  which  occur  in  pteridophy tes  is 
frequently  nearly  as  great  as  is  found  in  ordinary  seed- 
plants,  and  the  fibro-vascular  system  is  even  better  devel- 
oped in  many  ferns  than  in  some  seed-plants. 

Starch-making  is  carried  on  by  aid  of  abundant  chloro- 
phyll bodies  contained  in  parenchyma-cells  to  which  car- 
bonic acid  gas  is  admitted  by  stomata.  In  many  cases 
large  amounts  of  reserve  food  are  stored  in  extensive  root- 
stocks,  so  that  the  spring  growth  of  leaves  and  stems  is 
extremely  rapid. 


CHAPTER   XXIII 
THE    EVOLUTIONARY    HISTORY   OF   PLANTS 

368.  The  Earliest  Plant  Life.  —What  sort  of  plants  first 
appeared  on  the  earth  has  never  been  positively  ascertained. 
The  oldest  known  rocks  contain  carbon  (in  the  form  of 
black  lead  or  graphite)  which  may  represent  the  remnants 
of  plants  charred  at  so  high  a  temperature  and  under  so 
great  pressure  as  to  destroy  all  traces  of  plant  structure. 
Some  objects  supposed  by  many  to  be  the  remains  of  large 
alffse  have  been  found  in  rocks  that  date  back  to  a  very 

o  «/ 

early  period  in  the  life  history  of  the  earth,  before  there 
were  any  backboned  animals,  unless  possibly  some  fishes. 
Judging  from  the  way  in  which  the  various  groups  of 
plants  have  made  their  appearance  from  the  time  when 
we  can  begin  clearly  to  trace  their  introduction  upon  the 
earth,  it  is  probable  that  some  of  the  simplest  and  lowest 
forms  of  thallophytes  were  the  first  to  appear.  Decaying 
animal  or  vegetable  matter  must  have  been  less  abundant 
than  is  now  the  case,  so  that  a  plant  that  could  make 
part  Or  all  of  its  food  from  raw  materials  would  have  had 
a  better  chance  than  a  saprophyte  that  could  not.  Water- 
plants  are  usually  simpler  than  land-plants,  so  it  is  highly 
probable  that  some  kind  of  one-celled  aquatic  alga  was 
the  first  plant. 

369.  Fossil  Plants.  —  Fossils  are  the  remains  or  traces 
of  animals  or  plants   preserved  in  the  earth  by  natural 
processes.     Fossil  plants,    or   parts    of   plants,    are    very 

298 


THE  EVOLUTIONARY   HISTORY   OF  PLANTS          299 

common  ;  the  impressions  of  fern-leaves  in  bituminous  coal 
and  pieces  of  wood  turned  into  a  flint-like  substance  are 
two  of  the  best  known  examples. 

The  only  way  in  which  we  can  get  knowledge  about 
the  animals  and  plants  that  inhabited  the  earth's  surface 
before  men  did  is  by  studying  such  rocks  as  contain  the 
remains  of  living  things.  In  this  way  a  great  deal  of 
information  has  been  gained  about  early  forms  of  animal 
life  and  a  less  amount  about  early  plant  life,  —  less  because 
as  a  general  thing  plants  have  no  parts  that  would  be 
as  likely  to  be  preserved  in  the  rocks  as  are  the  bones 
and  teeth  of  the  higher  animals  and  the  shells  of  many 
lower  ones. 

370.  The  Law  of  Biogenesis.  —  An  extremely  important 
principle  established  by  the  study  of  the  development  of 
animals  and  plants  from  the  egg  or  the  seed,  respectively, 
to  maturity  is  this  :  The  development  of  every  individual  is 
a  brief  repetition  of  the  development  of  its  tribe.  The  prin- 
ciple just  stated  is  known  as  the  law  of  biogenesis.  As 
eggs  develop  during  the  process  of  incubation,  the  young 
animals  within  for  a  considerable  time  remain  much  alike, 
and  it  is  only  at  a  comparatively  late  stage  that  the  wing 
of  the  bird  shows  any  decided  difference  from  the  fore-leg 
of  the  alligator  or  the  turtle.  Zoologists  in  general  are 
agreed  that  this  likeness  in  the  early  stages  of  the  life 
history  of  such  different  -animals  proves  beyond  reasonable 
doubt  that  they  all  have  a  common  origin,  that  is,  are 
descended  from  the  same  kind  of  ancestral  animal. 

Among  plants  the  liverworts  and  ferns  supply  an  excel- 
lent illustration  of  the  same  principle.  In  both  of  the  groups 
the  fertilized  egg-cells,  as  the  student  may  have  learned 


300  FOUNDATIONS   OF   BOTANY 

by  his  own  observations,  are  much  alike.  As  the  egg-cell 
grows  and  develops,  the  sporophyte  of  a  liverwort,  which 
proceeds  from  the  egg-cell,  is  extraordinarily  unlike  the 
"  fern"  or  asexual  generation  (gametophyte)  among  Filices. 
Now  this  progressive  unlike  ness  between  liverworts  and 
ferns,  as  they  develop  from  the  fertilized  egg-cell,  points  to 
the  conclusion  that  both  groups  of  plants  have  a  common 
origin  or  that  the  more  highly  organized  ferns  are  direct 
descendants  of  the  less  highly  organized  liverworts. 

371.  Plants  form  an  Ascending  Series.  —  All  modern 
systems  of  classification  group  plants  in  such  a  way  as  to 
show  a  succession  of  steps,  often  irregular  and  broken, 
seldom  leading  straight  upward,  from  very  simple  forms 
to  highly  complex  ones.  The  humblest  thallophytes  are 
merely  single  cells,  usually  of  microscopic  size.  Class 
after  class  shows  an  increase  in  complexity  of  structure 
and  of  function  until  the  most  perfectly  organized  plants 
are  met  with  among  the  dicotyledonous  angiosperms. 
During  the  latter  half  of  the  present  century  it  first 
became  evident  to  botanists  that  among  plants  deep-seated 
resemblances  imply  actual  relationship,  the  plants  which 
resemble  each  other  most  are  most  closely  akin  by  descent, 
and  (if  it  were  not  for  the  fact  that  countless  forms  of  plant 
life  have  wholly  disappeared)  the  whole  vegetable  kingdom 
might  have  the  relationships  of  its  members  worked  out  by  a 
sufficiently  careful  study  of  the  life  histories  of  individual 
plants  and  the  likeness  and  differences  of  the  several  groups 
which  make  up  the  system  of  classification.1 

1  See  Campbell's  Evolution  of  Plants  and  Warming's  Systematic  Botany, 
Preface  and  throughout  the  work.  In  the  little  flora  of  the  present  book,  the 
families  are  arranged  in  the  order  which,  according  to  the  best  recent  German 
authorities,  most  nearly  represents  their  relationships. 


THE   EVOLUTIONARY    HISTORY   OF   PLANTS          301 

372.  Development  of  the  Plant  from  the  Spore  in  Green 
Algae,   Liverworts,  and  Mosses. — The   course  which   the 
forms  of  plant  life  have  followed  in  their  successive  ap- 
pearance on  the  earth  may  be  traced  by  the  application 
of  the  law  above  named.     Such  algse  as  the  pond-scums 
produce  spores  which  give  rise  directly  to  plants  like  the 
parent. 

In  many  liverworts  the  spore  by  its  germination  produces 
a  thallus  which  at  length  bears  antheridia  and  archegonia. 
The  fertilized  archegonium  develops  into  a  sporophyte 
which  remains. attached  to  the  thallus,  although  it  is  really 
a  new  organism.  Liverworts,  then,  show  an  alternation  of 
generations,  one  a  sexual  thallus,  the  gametophyte,  the 
next  a  much  smaller,  non-sexual  sporophyte,  and  so  on. 

A  moss-spore  in  germination  produces  a  thread-like  pro- 
tonema  which  appears  very  similar  to  green  algae  of  the 
pond-scum  sort.  This  at  length  develops  into  a  plant  with 
stem  and  leaves,  the  sexual  generation  of  the  moss.  The 
fertilized  archegonium  matures  into  a  sporophyte  which  is 
the  alternate,  non-sexual  generation.  This  is  attached  to 
the  moss-plant,  or  gametophyte,  but  is  an  important  new 
organism.  In  the  moss,  as  in  the  liverwort,  the  sexual 
generation  is  the  larger  and  the  more  complex  ;  the  non- 
sexual  generation  being  smaller  and  wholly  dependent  for 
its  food  supply  on  the  other  generation,  to  which  it  is 
attached. 

373.  Development  of  the  Plant  from  the  Spore  in  Pterido- 
phytes.  —  In  the  pteridophytes  there  is  an  alternation  of 
generations,  but  here  the  proportions  are   reversed,  the 
prothallium,  or  sexual  generation,  or  gametophyte,  being 
short-lived   and   small    (sometimes  microscopic),  and  the 


302 


FOUNDATIONS   OF   BOTANY 


non-sexual  generation,  the  sporophyte,  often  being  of  large 

size.  The  ferns  (non-sexual  generation),  for  instance,  are 
perennial  plants,  some  of  them  tree- 
like. 

Some  pteridophytes,  as  the  Salvinia, 
a  small  floating  aquatic  plant,  some- 
times known  as  a  water-fern  (Fig. 
215),  produce  two  kinds  of  spores, 
the  large  ones  known  as  macrospores, 
and  the  small  ones  known  as  micro- 
spores  (Fig.  216).  Both  kinds  pro- 
duce microscopic  prothallia,  those  of 
the  former  bearing  only  archegonia, 
those  of  the  latter  only  antheridia. 
From  the  prothallia  of  the  macro- 
spores  a  plant  (non-sexual  generation) 
of  considerable  complexity  of  struc- 
ture is  formed. 
374.  Parts  of  the  Flower  which  correspond  to  Spores.  — 

In  seed-plants  the  spore-formation  of  cryptogams  is  repre- 
sented,   though    in    a    way    not 

at    all    evident   without   careful 

explanation.       The   pistil  is  the 

macrospore-producing  leaf  or  mac- 

rosporophyll,   and  the  stamen  is 

the  microspore-producing  leaf  or 

microsporopTiyll.     Pines  and  other 

gymnosperms  produce  a  large  cell 

(the    embryo   sac)    in   the    ovule 

(Fig.  217),  which  corresponds  to  the  macrospore,  and  a 

pollen  grain    which   represents   the    microspore.      In  its 


FIG.  215.  — A  Water-Fern 
(Salvinia). 


FIG.  21 6.— Twolndusiaof  Salvinia. 

mi,  microspores  ;  ma,  macro- 
spores. 


THE    EVOLUTIONARY   HISTORY   OF   PLANTS 


303 


development  the  macrospore  produces  an  endosperm  which 
is  really  a  small  cellular  prothallium,  concealed  in  the  ovule. 
The  microspore  contains  vestiges  of  a  minute  prothallium. 

In  the  angiosperms  the  macrospore  and  its  prothallium 
are  still  less  developed,  and  the 
microspore,  or  pollen  grain,  has 
lost  all  traces  of  a  prothallium 
and  is  merely  an  antheridium 
which  contains  two  generative 
cells.1  These  are  most  easily 
seen  in  the  pollen  grain,  but 
sometimes  they  are  plainly  visi- 
ble in  the  pollen  tube  (Fig.  164). 
Phanerogams  are  distinguished 
from  all  other  plants  by  their 
power  of  producing  seeds,  or 
enclosed  macrosporangia,  with 
embryos. 

375,  The  Law  of  Biogenesis 
and  the  Relationships  of  the  Great 
Groups  of  Plants.  —  On  summing 
up  Sects.  372-374  it  is  evident 
that  the  sexual  generation  in 
general  occupies  a  less  and  less 
important  share  in  the  life  of  the 
plant  as  one  goes  higher  in  the  scale  of  plant  life.2  In  the 
case  of  the  rockweed,  for  instance,  the  sexual  generation 
is  the  plant.  Among  mosses  and  liverworts  the  sexual 

1  Sometimes  only  one  generative  cell  escapes  from  the  pollen  grain  into  the 
pollen  tube,  and  there  it  divides  into  two  cells. 

2  A  good  many  plants  of  low  organization,  however,  are  not  known  to  pass 
through  any  sexual  stage. 


FIG.  217.  — Longitudinal  Section 
through  Fertilized  Ovule  of  a 
Spruce. 

p,  pollen  grains  ;  t,  pollen  tubes  ; 
n,  neck  of  the  archegonium ; 
a,  body  of  archegonium  with 
nucleus  ;  e,  embryo  sac  filled 
with  endosperm. 


304  FOUNDATIONS   OF  BOTANY 

generation  is  still  very  prominent  in  the  life  of  the  plant. 
Ordinary  ferns  show  us  the  sexual  generation  existing  only 
as  a  tiny  independent  organism,  living  on  food  materials 
which  it  derives  from  the  earth  and  air.  In  the  Salvinia 
it  is  reduced  to  microscopic  size  and  is  wholly  dependent 
on  the  parent-plant  for  support.  Among  seed-plants  the 
sexual  generation  is  so  short-lived,  so  microscopic,  and  so 
largely  enclosed  by  the  tissues  of  the  flower  that  it  is  com- 
paratively hard  to  demonstrate  that  it  exists. 

The  fact  that  the  life  history  of  so  many  of  the  classes 
of  plants  embraces  a  sexual  stage,  in  which  an  egg-cell  is 
fertilized  by  some  sort  of  specialized  cell  produced  wholly 
for  use  in  fertilization,  tends  strongly  to  show  the  com- 
mon origin  of  the  plants  of  all  such  classes.  We  have 
reason  to  believe,  from  the  evidence  afforded  by  fossils, 
that  plants  which  have  only  a  sexual  generation  are 
among  the  oldest  on  the  earth.  It  is  therefore  likely  that 
those  which  spend  the  least  portion  of  their  entire  life  in 
the  sexual  condition  were  among  the  latest  of  plants  to 
appear.  Then,  too,  those  which  have  the  least  developed 
sexual  generation  are  among  the  latest  of  plants.  Judged 
by  these  tests  the  angiosperms  must  be  the  most  recently 
developed  of  all  plants. 

If  one  were  to  attempt  to  arrange  all  the  classes  of 
existing  plants  in  a  sort  of  branching  series  to  show  the 
way  in  which  the  higher  plants  have  actually  descended 
from  the  lower,  he  would  probably  put  some  one  of  the 
green  algae  at  the  bottom  and  the  angiosperms  at  the  top 
of  the  series. 

376.  The  Oldest  Angiosperms.  —  It  is  impossible  to  give 
any  of  the  reasons  for  the  statements  of  this  section 


THE   EVOLUTIONARY   HISTORY   OF  PLANTS          305 

without  making  an  unduly  long  chapter.  Briefly,  it  may 
be  stated  that  the  monocotyledons  are  the  simplest  and 
probably  the  oldest  angiosperms ;  the  dicotyledons  are 
higher  in  organization  and  came  later.  The  descent  and 
various  relationships  of  the  families  of  dicotyledons  can 
be  discovered  by  the  study  of  the  flower,  fruit,  and  seed 
better  than  by  the  examination  of  the  vegetative  organs. 

The  entire  pedigree  of  the  several  families  cannot  be 
represented  by  arranging  the  names  of  the  families  in  a 
straight  line.  It  is,  however,  in  a  general  way,  as  indi- 
cated by  the  succession  of  families  in  the  Flora  which 
accompanies  this  book,  the  Willow  Family  being  perhaps 
the  oldest  (of  the  more  familiar  ones)  and  the  Composite 
Family  the  youngest. 


PART  II 

ECOLOGY 

CHAPTER   XXIV 
PLANT   SOCIETIES 

377.  Ecology.  —  Plant  ecology  includes  all  that  portion 
of  botany  which  has  to  do  with  the  way  in  which  plants  get 
on  with  their  animal  and  plant  neighbors,  and  especially 
the  way  in  which  they  adjust  themselves  to  the  nature 
of  the  soil  and  climate  in  which  they  live.     Ecology,  in 
short,  discusses  the  relations  of  plants  to  their  surround- 
ings or  environment.     A  good  deal  of  what  has  been  said 
in  previous  chapters  about  such  topics  as  parasitic  plants, 
the  occurrence  of   winter   bud-scales,  the    movements  of 
leaves,   the    coating  of   hairs   on   stems   and  leaves,   the 
storage   of   water  in  epidermis-cells,  is   really  ecological 
botany,  although  it  is  not  so  designated  in  the  sections 
where  it  occurs. 

378.  Plant  Societies.  —  In  a  single  acre  of  woodland, 
of  marsh,  or  of  meadow,  there  will  usually  be  found  a 
large  number  of  species  of  plants.     One  species  may  be 
sufficiently  abundant  and  conspicuous  to  give  a  name  to 
the  whole  tract,  so  that  it  may,  for  instance,  be  recognized 
as  a  bit  of  birch  wood  or  of  cat-tail  swamp.     But  under 
the  birches  and  among  the  cat-tails  there  are  plants,  it  may 

307 


308  FOUNDATIONS   OF   BOTANY 

be,  of  a  hundred  other  kinds  —  the  seed-plants  —  not  all  in 
bloom  at  any  one  season,  but  coming  along  in  succession 
from  earliest  spring  until  the  approach  of  winter.  The 
entire  set  of  plants  which  naturally  occupies  a  given  area 
of  land  under  somewhat  uniform  conditions  is  called  a 
plant  society. 

379.  Similar  Societies  due  to  Similar  Conditions.  —  As 
soon  as  the  young  botanist  begins  to  collect  plants  in  a  set 
of  localities  new  to  him,  he  discovers  that  his  old  acquaint- 
ances are  still  to  be  found  grouped  as  he  has  been  accus- 
tomed to  see  them.  The  rich  black  loam  of  a  wooded 
bank  a  hundred  miles  away  from  his  familiar  collecting 
ground  will  show  the  same  assemblage  of  slippery  elms 
and  lindens,  red  buds,  bladdernuts,  and  wahoos,  hepaticas, 
bloodroots,  Dutchman's  breeches,  trilliums,  pepper  root,  and 
wild  ginger,  with  a  multitude  of  later-blooming  herba- 
ceous plants,  that  he  has  learned  to  know  so  well.  The 
muddy  borders  of  ponds  from  Maine  to  Minnesota  and 
beyond  are  fringed  with  the  same  kinds  of  bur-reeds  and 
sedges,  set  with  water-plantain,  and  decorated  with  the 
soft  white  blossoms  of  the  arrowhead.  The  sand  dunes 
along  the  northern  Atlantic  coast  and  those  that  border 
Lake  Michigan  are  clothed  with  a  sparse  vegetation  which 
in  both  cases  includes  the  little  beach  plum,  such  coarse 
grasses  as  that  shown  in  Plate  I,  and  the  straggling  sea 
rocket.  Barnyards  and  waste  grounds  about  farm  build- 
ings from  Massachusetts  to  Missouri  contain  such  weeds 
as  the  dog  fennel,  the  low  mallow  ("  cheeses"),  mother- 
wort,  catnip,  and  some  smartweeds. 

A  little  study  of  such  cases  soon  leads  one  to  the  con- 
clusion that  these  plant  societies  and  multitudes  of  others 


PLANT   SOCIETIES  309 

exist  because  all  the  plants  in  each  society  are  adapted  to 
their  special  environment.  Wherever  such  an  environment 
occurs  such  a  society  will  be  found  in  it,1  or,  if  not  already 
there,  will  nourish  when  introduced. 

380.  Similar  Species  replace  Each  Other Two  sets  of 

localities  alike  in  many  respects  but  unlike  in  some  points 
are  often  inhabited  by  different  species  of  the  same  genus. 
For  instance,  the  pine  barrens  of  New  England  and  the 
adjacent  states  are  commonly  covered  with  the  northern 
pitch  pine,  while  far  southward,  in  sandy  soil,  its  place 
is  taken  by  the  long-leaved  pine.  Along  streams  and 
swamps  northward  the  speckled  alder  is  generally  found, 
while  southward  the  smooth  alder  is  most  common.  In 
rich  woods  of  the  northeastern  United  States  the  painted 
trillium  and  the  erect  trillium  ("Benjamin,"  or  " squaw 
root ")  are  the  commonest  species,  while  far  south,  in  simi- 
lar localities,  the  sessile  trillium,  Underwood's  trillium, 
and  the  large-flowered  trillium  are  abundant. 

In  all  such  cases  —  and  they  are  very  numerous  —  we 
are  to  infer  that  the  genus  is  peculiarly  well  adapted  to 
some  especial  set  of  conditions,  as  sandy  soil,  brooksides,  or 
the  rich,  shaded  soil  of  woodlands.  But  the  more  northerly 
species  are  capable  of  enduring  the  severe  winters  and 
brief  summers  of  their  region,  while  the  more  southerly 
ones  perhaps  cannot  do  so.  The  relative  warmth  of  the 
climates  in  which  they  live  may  not  be  the  only  reason,  or 
even  the  principal  reason,  for  the  distribution  of  such 
plants  as  those  just  mentioned,  but  it  is  one  factor  at  any 
rate.  And  it  is  certain  that,  on  the  whole,  most  of  our 

1  That  is,  in  localities  not  separated  by  such  natural  barriers  as  seas,  high 
mountains,  or  deserts. 


810  FOUNDATIONS   OF  BOTANY 

native  and  thoroughly  naturalized  plants  are  growing 
under  what  is,  for  them,  the  best  environment,  since  they 
cannot  usually  be  made  to  exchange  places  with  each 
other.  If  a  square  mile  of  land  in  Louisiana  were  to  be 
planted  with  Minnesota  species,  and  a  square  mile  in 
Minnesota  with  Louisiana  species,  it  is  very  improbable 
that  either  tract,  if  left  to  itself,  would  long  retain  its 
artificial  flora.  To  this  rule  there  are,  however,  important 
exceptions  (see  Sect.  457). 

381.  Plant  Formations.  —  It  is  not  uncommon  to  find 
tracts   of  land   or  water  inhabited  by  great  numbers  of 
plants  of  the  same  species  so  as  almost  to  exclude   all 
other  plants  except  microscopic  cryptogams.     Ponds  and 
slowly  flowing  streams  are  often  filled  in  this  way  with 
the  water  hyacinth   or  the   American  lotus.      The  cane- 
brakes  of  the  south  and  the  wild  rice  swamps  along  north- 
ern lakes  and  rivers  are  other  examples  of  an  extremely 
simple  flora  spread  over  large  areas.     Prairies  not  infre- 
quently for  hundreds  of  square  miles  are  covered  mainly 
(not  entirely)   with  a  very  few  kinds  of  grasses.     Such 
assemblages  are  called  plant  formations  or  plant  colonies. 

382,  Ecological  Classification  of  Plants.  —  The  ordinary 
classification  of  plants,  as  set  forth  in  Chapter  XIX,  is 
based,  as  far  as  possible,  on  their  actual  relationships .  to 
each  other.     But  when  plants  are  classified  ecologically 
they  are  grouped  according  to  their  relations  to  the  world 
about  them.     They  may,  therefore,   be  gathered  into  as 
many  (or  more  than  as  many)  different  groups  as  there 
are  important  factors  influencing  their  modes  of  life.    We 
may  classify  plants  as  light-loving  and  darkness-loving, 
as  requiring  free  oxygen,  and  not  requiring  it,  and  so  on. 


PLANT   SOCIETIES  311 

Indeed,  one  of  the  most  useful  classifications  of  bacteria, 
for  practical  purposes,  is  into  species  which  must  have  free 
oxygen,  that  is,  oxygen  not  chemically  combined  with  other 
substances,  in  order  to  grow  and  increase,  and  those  which 
can  live  without  it. 

The  most  important  consideration  in  classifying  seed-  . 
plants  on  ecological  grounds  is  based  on  their  require-  / 
ments  in  regard  to  water.  Grouped  with  reference  to  ' 
this  factor  in  their  life  all  plants  may  be  classed  as  : 

(1)  Hydrophytes,  or  water-loving  plants. 

(2)  Xerophytes,  or  drought-loving  (or   perhaps    drought-tolerating) 

plants. 

(3)  Mesophytes,  or  plants  which  thrive  best  with  a  moderate  supply 

of  water. 

These  three  classes  do  not  fully  express  all  the  relations 
of  plants  to  the  water  supply,  so  two  others  are  found 
convenient. 

(4)  Tropophytes,  or  seasonal  plants  which  are  hydrophytes  during 

part  of  the  year  and  xerophytes  during  another  part.1 

(5)  Halophytes,  or  salt  marsh  plants  and  "  alkali "  plants,  species 

which  can  flourish  in  a  very  saline  soil. 

383.  Difficulties  in  Ecological  Classification.  —  It  seems 
at  first  sight  a  simple  matter  to  group  plants  in  regard  to 
their  need  of  water.  There  can  be  no  difficulty  in  classi- 
fying as  hydrophytes  all  plants  like  the  bladderworts,  water 
cresses,  certain  mosses,  and  many  lower  spore-plants  which 
live  only  in  water.  Cactuses,  aloes,  and  similar  plants  are 
recognized  at  sight  as  xerophytes.  But  the  chief  difficulty 

1  The  plants  which  E.  Warming,  one  of  the  foremost  authorities,  classes  as 
mesophytes  are  many  of  them  grouped  by  another  great  authority,  A.  F.  W. 
Schimper,  as  tropophytes. 


312 


FOUNDATIONS   OF   BOTANY 


is  in  dividing  mesophytes  from  the  other  two  classes,  into 
which  they  shade  by  indefinite  gradations.  In  order  to 
know  whether  the  plants  of  a  region  have  plenty  of  water 
or  not,  we  must  know  not  only  how  many  inches  of  yearly 
rainfall  there  are,  but  also  what  the  soil  is  like,  what  is 
the  temperature  of  the  soil  and  air,  whether  or  not  there 
are  dry  winds,  and  whether  there  are 
fogs  or  heavy  dews.  A  lichen  on  a 
bare  rock  may  be  living  almost  under 


FIG.  218.  —Aquatic  Plants  :  Pond-Lilies  with  Floating  Leaves  and 
Sedges  with  Aerial  Leaves. 

desert  conditions,  while  a  pitcher-plant  in  a  bog  near  by 
has  its  roots  in  standing  water  (or  in  ice)  nearly  all  the 
year  round. 

384.  Hydrophytes.  —  Some  of  these  are  herbaceous 
aquatic  plants,  like  the  duckweed,  the  pickerel-weed, 
the  pond-lily,  and  the  water-crowfoot ;  others,  such  as  the 
"calla"  (Richardia),  the  buckbean,  the  cat-tail,  and  the 
sweet  flag,  many  ferns,  mosses,  and  liverworts,  prefer 


PLANT   SOCIETIES 


313 


damp  air  and  soil.  All  of  tliem  transpire  freely,  and  many 
of  them  cannot  live  at  all  under  the  moisture  conditions 
which  suit  ordinary  plants. 

Some  aquatics  have  their  leaves  wholly  submerged, 
others,  such  as  the  duckweed  and  the  pond-lilies  (Fig.  218), 
have  them  floating,  and  still  others,  like  the  sedges  in  the 
same  picture,  have  their  leaves  freely  exposed  to  the  air. 
A  few  plants  have  both 
water-leaves  and  air-leaves 
(Fig.  219).  Soine  aquatic 
plants  are  rooted  in  the  mud, 
while  others  have  no  roots 
at  all,  or,  like  the  duckweed, 
have  only  water-roots. 

The  leaves  of  land-plants 
in  very  rainy,  subtropical 
climates  are  exposed  to  the 
attacks  of  parasitic  spore- 
plants  which  flourish  on 
their  surfaces.  To  ward  off 
the  attacks  of  these  it  is 
necessary  to  keep  water  from  accumulating  on  the  surfaces 
of  the  leaves.  This  result  is  secured  by  a  waxy  deposit  on 
the  epidermis  and  also  by  the  slender  prolongation  to  drain 
off  surplus  water,  shown  in  Fig.  221.  That  this  slender 
leaf  tip  is  useful  in  the  way  suggested  is  proved  by  the  fact 
that  when  it  is  cut  squarely  off  the  leaf  no  longer  sheds 
water  freely. 

385.  Xerophytes.  —  A  xerophyte  is  a  plant  which  is 
capable  of  sustaining  life  with  a  very  scanty  supply  of 
water.  Since  the  first  plants  which  existed  were  aquatics 


FIG.  219.  —  Submerged  and  Aerial  Leaves 
of  a  European  Crowfoot  (Ranunculus 
Purshii).  The  leaf  with  thread-like 
divisions  is  the  submerged  one. 


314 


FOUNDATIONS   OF   BOTANY 


FIG.  220.  —  The  Duckweed,  a  Floating 
Aquatic  Plant. 


(Sect.  368),  we  must 

^JSP^^ZTIZV  consider  that  xero 

¥S_~dSi^ pyhtes  are  highly  spe- 

cialized and  modified 
forms  adapted  to  ex- 
tremely trying  condi- 
tions of  life.  A  typical 
xerophyte  is  one  which 
can  live  in  a  very  dry 
soil  in  a  nearly  rain- 
less region.  The  yucca 
in  Plate  VII  and  the 
melon-cactus  (Fig.  49) 

are    good    examples    of   such   plants. 

Less  extremely  xerophytic  are  plants 

like   the  date-palm    (Fig.   54),  which 

flourishes  in  the  oases  of  the  Sahara, 

where    the    soil    is    moist    from    the 

presence  of  springs,  though  rains  are 

almost   unknown,    or   the    houseleeks 

and  stonecrops  found  in  many  gar- 
dens, the  so-called  Spanish  moss 

(Plate    IV),   and   lichens    (Figs.    198, 

199),  all  of  which  grow  most  rapidly 

in  moist  air,  but  cling  to  bare  rocks 

and  trunks  of  trees,  from  which  they 

get    no    water.      A    xerophyte    must 

be  capable  of  storing  water  and  tran- 

spiring    very    slowly,    like    cactuses, 

aloes,  Stonecrops,  and  SUCh  fleshy  plants  with  a  Slender  Taper- 

ing Point  to  drain  off 
1  Ficus  religiosa.  Water. 


PLANT  SOCIP:TIES 


315 


FlG.  222.  —  A  Field  of  Prickly-Pear  Cactus  Plants  :  Xerophytes. 


316 


FOUNDATIONS   OF   BOTANY 


with  a  thick  epidermis^  or  else  it  must  be  able  to  revive 
after  being  thoroughly  dried.  A  few  seed-plants  and 
many  such  spore-plants  as  lichens,  Pleurococcus  (Sect. 
277),  yeast,  and  some  bacteria  (Sect.  263),  thrive  just  as 
well  after  remaining  for  some  months 
or  years  in  a  dried  condition  as  they 
did  before  drying.  A  good  illustration 
of  this  fact  as  regards  yeast  is  found  in 
the  use  of  dried  yeast  cakes,  made  of  a 
mixture  of  yeast  and  corn  meal.  These 
will  raise  dough  promptly  when  mixed 
with  it,  even  if  they  have  been  kept 
dry  for  a  year  or  more. 

386.  Roots  and  Stems  of  Xerophytic 
Seed-Plants.  —  Some  xerophytes  have 
roots  which  show  no  peculiarities  of 
form  or  structure,  but  many  make  special 
provision  for  storing  food  and  water  in 
their  roots.  Such  roots  are  fleshy  and 
often,  as  in  Harpagophytum  (Fig.  223), 
are  of  great  size  compared  with  the 
portion  of  the  plant  above  the  ground. 
Xerophytic  stems  are  frequently  very 
thick  in  proportion  to  their  length, 
sometimes  even  globular,  and  they 
commonly  contain  large  amounts  of  water.  In  leafless 
plants,  like  the  cacti,  the  surface  for  transpiration  is  much 
less  than  that  offered  by  leafy  plants.  Many  species  which 
bear  leaves  shed  most  of  them  at  the  beginning  of  the  dry 
season,  and  some  remain  thus  in  a  half  dormant  condi- 
tion for  long  periods,  as  is  the  case  with  many  Euphorbias 


FIG.  223.  —  Harpago- 
phytum, a  South 
African  Xerophyte. 


PLATE  VII.  —  Tree  Yucca  in  the  Mohave  Desert 


PLANT   SOCIETIES  317 

(Fig.  245).  The  epidermis,  even  on  the  younger  portions 
of  the  stem,  is  highly  cutinized  (Fig.  121),  and  this  structure 
makes  any  evaporation  very  slow. 

387.  Leaves  of   Xerophytes.  —  In    regions    where   the 
greatest  dangers  to  vegetation  arise  from  long  droughts 
and  the  excessive  heat  of  the  sun,  the  leaves  of  plants 
usually  offer  much  less  surface  to  the  sun  and  air  than  is 
the  case  in  temper- 

ate  climates.  Some- 
times the  blade  of 
the  leaf  is  absent 
and  the  expanded 
petiole  answers  the 
purpose  of  a  blade, 

Or,    again,    foliage       FIG.  224.  —  Cross-Section  of  Rolled-Up  Leaf  of  Crow- 
leaveS    are    altO-  Berry  (Empetrum  nigruin).    (Magnified.) 

gether  lacking,  as  in  the  cactuses  (Fig.  222),  and  the  green 
outer  layers  of  the  stem  do  the  work  of  the  leaves. 

388.  Rolled-Up  Leaves.  —  Leaves  which  receive  but  a 
scanty  supply  of  water  are  often  protected  from  losing  it 
too  rapidly  by  being  rolled  up,  so  that  the  evaporating, 
i.e.,  stomata-containing,  surface  is  on  the  inside  of  the  roll. 
Sometimes,  as  in  the  crow-berry  (Fig.  224),  the  curled  con- 
dition is  permanent.     In  other  plants,  as  in  such  grasses 
as  Stipa  (Fig.  225),  and  in  Indian  corn,  the  leaf  rolls  up 
when  the  weather  is  very  dry  and  unrolls  again  when  it 
receives  a  better  supply  of  water. 

389.  Mesophytes.  —  A    mesophyte    is    a    plant    which 
thrives  best  with  a  moderate  supply  of  water.     The  great 
majority  of   the  wild    and   the  cultivated    plants  of   the 
United  States  are  mesophytes,  and  what  has  been  learned 


318  FOUNDATIONS   OF   BOTANY 

from  Part  I  of  this  book  about  the  forms,  structure,  and 
habits  of  ordinary  plants,  together  with  what  the  student's 
own  observation,  aside  from  the  study  of  botany,  has  taught 
him,  should  suffice  to  give  him  a  fair  idea  of  mesophytic 
plant  life. 

The  typical  mesophyte  of  the  northern  United  States  is 
an  annual,  since  most  of  our  larger  perennials  pass  the 
winter  in  a  xerophytic  condition,  to  avoid  destruction  by 
drying  up  during  the  long  period  when 
the  roots  can  absorb  little  or  no  water 


FIG.  225.  —  Cross-Section  of  Leaves  of  a  Grass,1  unrolled  for  Exposure  to 
Sunlight  and  rolled  up  to  prevent  Evaporation. 

r,  ridges  of  the  upper  epidermis,  with  many  stomata  on  their  surfaces ; 
e,  thick  lower  epidermis,  without  stomata. 

from  the  frozen  soil.  Our  evergreen  coniferous  trees, 
such  as  pines,  spruces,  cedars,  and  so  on,  have  leaves  of 
decidedly  xerophytic  structure.  So  also  do  such  ever- 
green shrubs  as  the  rhododendrons,  wintergreen,  arbutus, 
holly,  and  bearberry.  Our  deciduous  trees  and  shrubs  and 
most  perennial  herbs  are  tropophytes  (Sect.  390). 

390.  Tropophytes,  or  Seasonal  Plants.  —  Examples  of 
these  are  most  deciduous  trees  and  the  majority  of  the 
perennials  of  temperate  regions,  for  instance  oaks,  elms, 
birches  among  trees,  and  tulips,  crown  imperials,  lilies, 
hyacinths,  spring-beauties,  peonies,  dahlias,  and  potatoes 
among  herbs.  Such  plants  have  a  pretty  large  surface  for 

1  Stipa  capillata. 


PLANT   SOCIETIES 


319 


transpiration  during  the  summer  (or  in  regions  like  South- 
ern California  in  the  rainy  season)  and  a  greatly  reduced 
surface  during  the  winter  (or  the  dry  season). 

In  the  case  of  trees  the  reduction  of  surface  is  brought 
about  by  the  fall  of  the  leaves  (Sect.  186),  and  in  the  case 
of  herbaceous  perennials  it  is  secured*  by  the  death  of  the 
green  stem  and  the  leaves,  so  that  only  a  compact  root, 
rootstock,  or  bulb  is  left  alive  underground.  That  is  to 
say,  the  perishable  or  annual  part  of  tropophytes  has  the 
characteristics  of  mesophytes  or  even  of  moisture-loving 
plants,  while  the  perennial  part  is  constructed  on  the  plan 
of  xerophytes. 

391.  Halophytes.  —  A  halophyte  is  a  plant  which  can 
thrive  in  a  soil  containing  much  common  salt  or  other 
saline  substances.  The  seaside  obviously  occurs  to  one  as 
the  region  of  halo- 
phytic  vegetation, 
but  many  inland 
areas  contain  halo- 
phytic  plants,  for 
instance  the  neigh- 
borhoods about  salt 
springs  and  the 
"  alkali "  lands  of 
the  southwest  and 
the  Pacific  Slope. 
The  presence  of  salt 
in  the  soil  renders 
absorption  of  the 
soil-water  comparatively  difficult,  since  osmosis  takes  place 
more  readily  between  ordinary  water  and  the  liquid 


FIG.  226.  —  The  Mangrove,  a  Halophytic  Tree  of 
Southern  Florida  and  the  Tropics. 


320  FOUNDATIONS    OF   BOTANY 

contents  of  root-hairs  and  young  roots  than  between  salt 
water  and  the  liquids  inside  the  root.  Halophytes,  there- 
fore, are  put  on  short  rations  as  regards  water,  even 
though  they  may  be  growing  in  a  watery  marsh.  Con- 
sequently halophytes  often  have  much  the  appearance  of 
fleshy  xerophytes  and  the  structure  of  xerophytes. 

The  mangrove  tree  (Fig.  226)  is  one  of  the  most  remark- 
able of  halophytes.  It  grows  in  shallow  water  along  the 
seashore  and  sends  out  many  aerial  roots  which  at  length 
find  their  way  down  into  the  salt  mud.  In  this  way  it 
collects  drift  material  and  gradually  extends  the  shore  line 
farther  out  to  sea. 

392.  Other  Kinds  of  Ecological  Classes.  —  It  is  easy  to 
class  plants  according  to  their  habits  in  many  other  regards 
than  according  to  their  relative  power  of  transpiration  (see 
Chapter  XXVI).  Only  one  other  kind  of  classification 
need,  however,  be  mentioned  in  this  chapter,  that  is,  the 
division  into  sun-loving  and  shade-loving  plants.  Even  in 
very  dense  forests  some  plants  will  be  found  growing  on 
the  soil  in  the  twilight  formed  by  the  shade  of  the  trees. 
Some  of  this  undergrowth  is  of  seed-plants,  and  there  are 
many  ferns  and  mosses  which  flourish  in  such  situations. 
Shade-plants  commonly  have  large  pale  leaves,  and  gener- 
ally (except  in  ferns)  the  leaves  are  not  much  cut  or 
lobed  (Fig.  227, 1).  Sun-loving  plants,  on  the  other  hand, 
usually  have  comparatively  little  leaf-surface,  and  the 
leaves  are  often  cut  into  narrow  divisions  (Fig.  227,  II). 
Apparently  the  broad  leaf-surfaces  in  the  one  class  are  to 
expose  many  green  cells  to  the  light  for  starch-making, 
while  in  the  other  class  the  slender  leaf-divisions  expose 
enough  assimilating  cells,  and  at  the  same  time  the 


PLANT   SOCIETIES 


321 


narrowness  of  the  division  permits  plenty  of  light  to 
penetrate  to  the  plant's  lower  leaves.  It  is  also,  doubt- 
less, much  easier  for  leaves  like  those  of  the  yarrow,  the 
dog  fennel,  the  tansy,  the  carrot,  and  their  like,  to  with- 
stand the  action  of 
severe  winds,  to 
which  they  are  often 
exposed,  than  it 
would  be  for  leaves 
like  those  of  the  jack- 
in-the-pulpit  (see 
Frontispiece),  the 
trilliums,  the  lily-of- 
the- valley,  and  simi- 
lar leaves. 

393,  Transition  of 
a  Plant  from  Shade 
Conditions  to  Sun 
Conditions.  —  It  is 
characteristic  of 
many  kinds  of  forest 
trees  that  the  young 
seedlings  are  much 
more  tolerant  of 
dense  shade  than  the 
adult  trees  are. 
Sometimes  their  seeds  will  hardly  germinate  at  all  unless 
thoroughly  shaded,  and  the  young  trees  for  the  first  few 
years  flourish  best  in  the  shade.  Afterwards  most  trees 
need  a  good  deal  of  sunlight,  but  they  may  live  long 
with  a  scanty  supply  of  light.  The  red  spruce  sometimes 


i  ii 

Fi<i.  227.  —  I,  a  Shade-Plant  (Clintonia) ;  II,  a  Sun- 
Plant,  Dog  Fennel  (Maruta). 


322 


FOUNDATIONS   OF   BOTANY 


FIG.  228.  —  An  Epiphytic  Fern  (Platycerium)  on  a  Tree  Trunk. 

The  more  upright  leaves  next  the  trunk  of  the  tree  serve  to  collect  water 
and  to  accumulate  a  deposit  of  decaying  vegetable  matter,  while  the 
outer  leaves  serve  as  foliage  and  bear  spores. 


PLANT   SOCIETIES  323 

lingers  on  for  fifty  or  a  hundred  years,  reaching  meantime 
a  diameter  of  not  more  than  two  inches,  and  then,  on 
getting  more  light,  shoots  up  into  a  large  and  valuable 
timber  tree.1 

394.  Epiphytes.  —  It  is  even  easier  for  a  plant  to  secure 
enough  sunlight  in  a  forest  region  by  perching  itself  upon 
the  trunk  or  branches  of  a  tree  than  by  climbing,  as  our 
wild  grapevines  and  the  great  tropical  lianas  do.  There 
is  a  large  number  of  such  perched  plants,  or  epiphytes, 
embracing  species  of  many  different  groups  of  seed-plants 
and  of  spore-plants.  The  fern  shown  in  Fig.  228  is  a  good 
example  of  an  epiphyte.  Instances  among  seed-plants  are 
the  so-called  Florida  moss  (Plate  IV)  and  orchids  like 
those  in  Fig.  13. 

1  See  the  Primer  of  Forestry,  Part  I,  U.  S.  Department  of  Agriculture, 
1899,  pp.  33-35. 


CHAPTER   XXV 
BOTANICAL    GEOGRAPHY 

395.  Regions  of  Vegetation.  —  The  earth's  surface  (that 
of  the  land)  has  been  described  by  one  of  the  greatest  of 
geographical  botanists 1  as  divided  into  twenty-four  regions 
of  vegetation.     This  classification  takes  account  of  all  the 
principal  continental  areas  which  have  a  characteristic  set 
of  plants  of  their  own,  as  well  as  of  the  most  important 
islands.     But  a  simpler  arrangement  is  to  consider  the 
plant  life  of  the  earth  as  distributed  among  the  following 

regions : 

1.  The  tropical  zone. 

2.  The  temperate  zones. 

3.  The  arctic  zones. 

4.  Mountain-heights. 

5.  Bodies  of  water. 

Any  good  geography  gives  some  account  of  at  least  the 
land  vegetation  of  the  earth.  It  is  necessary  in  the  pres- 
ent chapter  only  to  point  out  a  few  of  the  most  important 
characteristics  of  the  plants  of  the  zones  and  other  areas 
mentioned  above  and  to  give  some  reasons  why  the  plant 
population  of  each  has  its  special  characteristics. 

396.  Tropical  Vegetation.  —  Within  the  tropics  two  of 
the  great  factors  of  plant  life  and  growth,  namely,  light 
and  heat,  are  found  in  a  higher  degree  than  elsewhere 
on  the  earth.     Moisture,  the  third  requisite,  is  in  some 

1  A,  Grisebach, 
324 


BOTANICAL  GEOGRAPHY  325 

regions  very  abundant  (over  sixteen  feet  of  rainfall  in  a 
year)  or  sometimes,  in  desert  areas,  almost  lacking.  We 
find  here,  accordingly,  the  greatest  extremes  in  amount 
of  vegetation,  from  the  bare  sands  or  rocks  of  the  Sahara 
desert  (Fig.  229)  to  the  densely  wooded  basin  of  the 
Kongo  and  of  the  Amazon.  Xerophytic  plants,  many  of 
them  with  extremely  complete  adaptations  for  supporting 
life  for  long  periods  without  water,  are  characteristic  of 
tropical  deserts,  while  many  of  the  most,  decided  hydro- 
phytes among  land-plants  are  found  in  the  dripping  sub- 


FIG.  229.  — Hills  of  Drifted  Sand  in  the  Sahara. 

tropical  forest  interiors.  Throughout  a  large  part  of  the 
zone,  reaching  five  degrees  each  way  from  the  equator, 
there  are  daily  rains  the  year  round. 

397.  Vegetation  of  the  Temperate  Zones.  —  We  are  all 
familiar  in  a  general  way  with  the  nature  of  the  plant 
life  of  the  north  temperate  zone ;  that  of  the  south 
temperate  is  in  most  ways  similar  to  our  own.  Most  of 
the  annuals  and  biennials  are  of  a  medium  type,  not 
decided  xerophytes  nor  hydrophytes,  and  the  perennials 
are  mainly  tropophytes.  There  are  no  desert  areas  so 
large  or  so  nearly  destitute  of  plants  as  those  found  in 
subtropical  regions,  neither  are  there  any  such  luxuriant 


326 


FOUNDATIONS   OF   BOTANY 


growths  as  occur  in  the  rainy  forest  regions  of  the  tropics. 
On  the  other  hand,  the  largest  trees  on  earth,  the  "big 
trees,"  or  Sequoias  (Fig.  32),  occur  in  the  temperate  por- 
tion of  North  America,  along  the  Sierra  Nevada,  and 
the  taller,  though  less  bulky,  gum  trees  (Eucalyptus)  of 
Australia  grow  in  a  warm  temperate  region. 

398.  Temperate  Plant  Societies  due  to  Special  Conditions 
of  Soil.  —  Even  where  the  climate 
is  a  moderate  one  as  regards  tem- 
perature and  rainfall,  peculiar 
soils  may  cause  the  assemblage 
of  exceptional  plant  societies. 
Some  of  the  most  notable  of 
such  societies  in  temperate  North 
America  are  those  of  the  salt 
marshes,  the  sand  dunes,  and  the 
peat  bogs. 

In  salt  marshes  the  water  sup- 
ply is  abundant,  but  plants  do  not 
readily  absorb  salt  water  by  their 
roots,  so  that  the  plants  which 
grow  in  salt  marshes  usually  have 
something  of  the  structure  and  appearance  of  xerophytes. 
Some  of  them  are  fleshy  (Fig.  230),  and  some  species  are 
practically  leafless. 

Sand  dunes,  whether  along  the  seacoast  or  near  the 
great  lakes,  offer  a  scanty  water  supply  to  the  roots  dur- 
ing much  of  the  year,  and  the  soil-water  contains  less  of 
the  raw  materials  for  plant  food  than  is  offered  by  that 
of  ordinary  soils.  Many  grasses  thrive,  however,  in  these 
shifting  sands  (Plate  I),  and  some,  like  the  beach-grass 


FIG.  230.  —  A  Halophytic  Plant 
(Salicomia). 


BOTANICAL   GEOGRAPHY 


327 


(AmmopTiild)  of  the  Atlantic  coast  and  the  great  lakes, 
will  continue  to  grow  upward  as  the  sand  is  piled  about 

them  by  the  winds  until  they 
have  risen  to  a  level  of  a 
hundred  feet  above  the  start- 
ing point. 

Peat    bogs    are    especially 
characterized  by  the  predominance  of 
the  peat  mosses  (Fig.  231)  from  which 
they  take  their  name. 
These  plants  and  the  others  which  associ- 
ate with  them  are  mostly  hydrophytes,  living 
usually  with  a  considerable  portion  of  the 
plant    continually   submerged   in   the    bog 
water.     The  water  of  such  bogs  contains 
little  mineral  matter  and  only  a  very  scanty 
supply  of  nitrogen,  in  the  form  of  nitrates 
dissolved  in  it.     The  bog-plants,  therefore, 
must  either  get  on  with  an  exceptionally 
small  supply  of  nitrogen  or  they  must  get 
it  from  an  unusual  source.     The  peat  mosses 
adopt  the  former  alternative,  while  the  sun 
dews   (Fig.   238),   the    pitcher-plants    (Fig. 
237),  and  some  other  species  adopt  the  latter  and 
derive  their  nitrogen  supply  largely  from  insects 
which  they  catch,  kill,  and  digest. 

399.  Arctic  Vegetation.  —  The  seed-plants  of  the 
arctic  flora  are  mostly  perennials,  never  trees. 
gy  tlie  ^gQ  ^\^  of  the  underground  portion 
as  compared  with  that  of  the  part  above  ground,  they 
are  adapted  to  a  climate  in  which  they  must  lie  dormant 


FIG.  231. 
Peat  MOSS 


328  FOUNDATIONS   OF  BOTANY 

for  not  less  than  nine  months  of  the  year.  The  flowers 
are  often  showy  and  appear  very  quickly  after  the  brief 
summer  begins.  Mosses  and  lichens  are  abundant,  —  the 
latter  of  economical  importance  because  they  furnish  a 
considerable  part  of  the  food  of  reindeer. 

400.    Mountain  or  Alpine  Vegetation In  a  general  way 

the  effect  of  ascending  a  mountain,  so  far  as  vegetation  is 


FIG.  232.  —  A  Plant  of  Arctic  Willow.     (About  natural  size.) 

concerned,  is  like  that  of  traveling  into  colder  regions. 
It  was  long  ago  suggested,  in  regard  to  Mount  Ararat, 
that  on  ascending  it  one  traversed  first  an  Armenian,  then 
a  South  European,  then  a  French,  then  a  Scandinavian, 
and  finally  an  arctic  flora.  Up  to  a  certain  height,  which 
varies  in  different  latitudes,  the  slopes  of  mountains  are 
very  commonly  forest-covered.  The  altitude  up  to  which 
trees  can  grow  (or  as  it  is  commonly  called  in  this  country 
the  "  timber  line  ")  is  somewhat  over  twelve  thousand  feet 


BOTANICAL  GEOGRAPHY 


329 


in  the  equatorial  Andes  and  lessens  in  higher  latitudes  as 
one  goes  either  way  from  the  equator.  In  the  White 
Mountains,  for  instance,  the  timber  line  only  rises  to  about 
four  thousand  five  hundred  feet.  The  seed-plants  of  alpine 
regions  in  all  parts  of  the  earth  have  a  peculiar  and  charac- 
teristic appearance.  It  is  easiest  to  show  how  such  plants 
differ  from  those  of  the  same  species  as  they  look  when 


FIG.  233.  —  Trees  near  the  Timber  Line  on  tlie  Slope  of  Pikes  Peak. 

growing  in  ordinary  situations  by  reference  to  the  plants 
themselves  or  to  good  pictures  of  them  (see  Fig.  285). 
The  differences  between  alpine  and  non-alpine  plants  of 
the  same  or  closely  related  species  have  been  summed  up 
as  follows : l 

"The  alpine  individuals  have  shorter  stems,  smaller  leaves, 
more  strongly  developed  roots,  equally  large  or  somewhat 
larger  and  usually  somewhat  more  deeply  colored  flowers, 
and  their  whole  structure  is  drought-loving  (xerophilous)." 

1  By  A.  F.  W.  Schimper. 


330 


FOUNDATIONS   OF   BOTANY 


FIG.  234.  —  Decrease  in  Size  of  Trees  at  High  Elevations  (Canadian  Rockies). 

Trees  at  great  elevations  become  much  gnarled  and 
stunted,  as  their  growth  is  necessarily  very  slow  (Fig. 
233).  The  gradual  diminution  of  the  height  of  the 


BOTANICAL   GEOGRAPHY 


381 


trees  on  ascending  a  mountain  is  well  shown  in  Fig.  234. 
The  treeless  character  of  the  mountain  summit  is  also 
plain.1 

Recent  experiments  have  shown  that  many  ordinary 
plants  promptly  take  on  alpine  characteristics  when  they 
are  transferred  to  moderate  heights  on  mountains.  For 
instance,  a  rather 
commonly  culti- 
vated sunflower,2 
when  planted  at  a 
height  of  about  six 
thousand  five  hun- 
dred feet,  instead 
of  having  a  tall 
leafy  stem  pro- 
duces a  rosette  of 
veiy  hairy  leaves 
lying  close  to  the 
ground,  thus  be- 
coming almost  un- 
recognizable as  a 
sunflower.  The 

Change     Was      even 
greater     than     that 

shown  in  the  rock 
rose  (Fig.  235)  cultivated  by  the  same  experimenter.  The 
peculiarities  of  alpine  plants  appear  to  be  due  mainly  to 
the  intense  light  which  they  receive  during  the  daytime, 

1  Part  of  the  diminution  is  only  apparent,  —  the  effect  of  distance,  —  but  the 
growth  at  the  highest  levels  is  often  less  than  waist  high. 

2  Helianthus  tuberosus,  the  so-called  Jerusalem  artichoke. 


_  TWQ  plantg  Qf  Kock  ^^  (Helianthemum). 
(Both  drawn  to  the  same  scale.) 

low  sround  form  '  *•  alpine  form' 


332  FOUNDATIONS   OF   BOTANY 

to  the  strongly  drying  character  of  the  air  in  which  they 
grow  (due  partly  to  its  rarefaction),  and  to  the  low  temper- 
ature which  they  must  endure  every  night. 

401.  Aquatic  Vegetation.  —  Plants  which  live  wholly  in 
water  often  need  a  less  complicated  system  of  organs  than 
land-plants.  True  roots  may  be  dispensed  with  altogether, 
as  in  many  seaweeds,  in  most  fresh-water  algse,  and  in 
some  seed-plants.  A  few  such  plants  have  mere  hold- 
fasts that  keep  them  from  drifting  with  the  waves  or  the 
current.  Sometimes  roots  may,  as  in  the  duckweeds 
(Fig.  220),  serve  the  purpose  of  a  keel  and  keep  the 
flat,  expanded  part  of  the  plant  from  turning  bottom  up. 
The  tissues  that  give  strength  to  the  stems  and  leaves  of 
land-plants  are  not  usually  much  developed  in  submerged 
aquatics,  since  the  water  supports  the  weight  of  such 
plants.  In  some  algae,  as  the  common  rockweed  or  blad- 
der-wrack (Fig.  183),  the  weight  of  the  plant  is  admi- 
rably buoyed  up  by  large  air-bladders.  Transpiration  is 
done  away  with,  and  whatever  carbonic  acid  gas  or  oxygen 
is  absorbed  or  given  off  passes  directly  through  the  cell- 
walls  into  the  interiors  of  the  cells.  Generally  water- 
plaats  do  not  reach  any  great  size,  but  some  species  are 
the  longest  of  known  plants,  Macrocystis,  the  great  kelp 
of  the  Pacific  Ocean,  attaining,  it  is  said,  the  length  of  a 
thousand  feet  or  more.  In  spite  of  the  moderate  size  of 
most  algse  the  total  bulk  in  the  various  oceans  must  be 
extremely  large.  The  Sargasso  Sea  alone,  in  the  Atlantic 
Ocean,  reaches  most  of  the  way  from  the  Bahamas  to  the 
Azores  and  extends  over  seventeen  degrees  of  latitude. 
The  whole  area  is  occupied  by  a  nearly  compact  mass  of 
floating  seaweed. 


BOTANICAL  GEOGRAPHY  333 

Besides  the  comparatively  well-known  and  readily  seen 
larger  algae  there  is  a  great  amount  of  vegetation  floating 
in  what  is  known  as  the  plankton.  This  is  a  mass  of 
microscopic  animals  and  plants,  found  floating  scum-like 
or  submerged  in  fresh  and  in  salt  water  and  often  accu- 
mulated in  great  quantities  near  shores,  to  which  it  is 
swept  by  the  action  of  the  wind  and  waves  and  currents. 
Much  of  the  plant  life  of  the  plankton,  both  of  fresh  and 
of  salt  water,  often  consists  of  the  flinty-shelled  one-celled 
microscopic  algse  known  as  diatoms  (Fig.  176). 

402.  Botanical  Geography  of  the  United  States.  —  All  of 
the  continuous  territory  of  the  United  States  1  lies  in  the 
north  temperate  zone.  There  is  material  for  a  large  vol- 
ume in  the  discussion  of  the  distribution  of  plants  over 
our  territory  in  this  continent  alone,  but  it  is  possible  to 
sum  up  a  mere  outline  of  the  matter  in  a  very  few  words. 
Excluding  the  floras  of  many  single  mountains  and  moun- 
tain ranges,  the  land  surface  of  the  country  may  for  botan- 
ical purposes  be  divided  into  four  great  areas,  as  follows : 

1.  The  Forest  Region.  —  This  occupies  the  eastern  and 
central  portion  of  the  United  States.     It  is  bounded  on 
the  west  by  an  irregular  line,  most  of  which  lies  to  the 
eastward  of  the  hundredth  meridian.     In  some  places  this 
forest  boundary  extends  eastward  across  the  Mississippi 
River,  while    in    others    it  recedes    from   the    river   five 
hundred  miles  or  more  to  the  westward. 

2.  The  G-reat  Plains  Region.  —  This  extends  westward 
from    the    region   above  named  to   the   Rocky  Mountain 
Plateau. 

1  That  is,  not  counting  in  Alaska,  our  West  Indian  possessions,  the  Sand- 
wich Islands,  or  the  Philippines. 


334  FOUNDATIONS   OF   BOTANY 

3.  The  Pacific  Highland  Region.  —  This  includes    the 
Rocky  Mountains,   the  Sierra  Nevada,   and  the    various 
plateaus  between  them. 

4.  The  Pacific  Slope.  —  This  extends  from  the  Cascade 
Range  and  the  Sierra  Nevada  to  the  sea. 

403.  Characteristics  of  the  Four  Regions.  —  The  forest 
region  is  mainly  remarkable  for  its  great  variety  of  hard- 
wood trees,  of  which  it  contains  a  larger  number  of 
useful  species  than  any  equal  area  of  the  earth  with  a 
temperate  climate.  In  the  northeasterly  portion  and  in 
much  of  the  southerly  portion  there  are  extensive  forests 
of  the  cone-bearing  evergreens,  such  as  pines,  spruces, 
hemlocks,  and  cedars.  The  vegetation  is  in  general 
such  as  thrives  in  medium  conditions  as  regards  heat 
and  rainfall. 

The  plains  region  is  largely  covered  with  grasses,  many 
of  them  xerophytes.  Some  of  the  most  characteristic  plants 
associated  with  the  grasses  are  Composite,  such  as  sun- 
flowers, rosin-weeds  (Silphium),  cone-flowers,  gum-weeds 
(G-rindelia),  and  blazing-stars  (Liatris). 

The  Pacific  highland  region  includes  a  very  great  vari- 
ety of  plant  societies,  from  the  heavily  wooded  mountain 
slopes  and  valleys  to  high  sterile  plains  which  are  almost 
deserts.  Cone-bearing  evergreen  trees  are  very  character- 
istic of  the  forests.  Great  numbers  of  alpine  species  of 
herbs  and  shrubs  are  found  on  the  mountains  at  and  above 
the  timber  line.  In  the  alkali  regions,  where  the  soil  is 
too  full  of  mineral  salts  to  permit  ordinary  plants  to  grow, 
many  kinds  of  xerophytes,  such  as  the  salty  sage  (Atriplex) 
and  the  greasewood  (Sarcobatue),  occur.  In  the  southern 
portion  cactuses  abound. 


o 

3 
CK5 

P 
GC 
3 


•JL 


BOTANICAL   GEOGRAPHY  335 

The  Pacific  Slope  is  characterized  by  cone-bearing  ever- 
greens in  great  abundance  in  the  mountains  and  along  the 
foothills.  Chief  among  these  in  point  of  size  are  the  red- 
woods and  the  "big  trees"  (Sequoias)  (Fig.  32).  Oaks 
are  represented  by  a  good  many  species,  several  of  them 
evergreen.  There  are  many  xerophytes,  some  of  them 
characteristic  of  alkali  regions;  and  in  Southern  California, 
on  account  of  the  long  dry  season,  plants  with  large  roots 
or  rootstocks  and  bulb-bearing  plants  (many  of  them 
belonging  to  the  lily  family)  are  abundant.  The  tree 
yucca  (P-late  VII)  is  one  of  the  largest  and  most  inter- 
esting xerophytic  plants  of  North  America. 


CHAPTER   XXVI 

PARASITES,  ENSLAVED  PLANTS,  MESSMATES, 
CARNIVOROUS  PLANTS 

404.  Parasites.  —  A  little  was  said  in  Chapter  IV  about 
parasitic  plants,  and  the  life  history  of  one  of  them,  the 
dodder,  was  briefly  outlined  ;  another,  the  wheat  rust,  was 
discussed  in   Sects.  310-313.     A  parasitic  plant  is   one 
which  draws  its  supply  of  food  partially  or  wholly  from 
another  living  plant  or  animal  known  as  the  host.     Some 
parasites   are   seed-plants,   but  a   far  greater  number  of 
species  are  spore-plants. 

405.  Half -Parasitic  Seed-Plants.  —  Half-parasites  or  par- 
tial parasites  are  those  which  take  a  portion  of  their  food  (or 
of  raw  materials  to  make  food)  from  their  host  and  manu- 
facture the  rest  for  themselves.     Usually  they  take  mainly 
the  newly  absorbed  soil-water  from  the  host  and  do  their 
own  starch-making  by  combining  the  carbonic  acid  gas, 
which  they  absorb  through  their  leaves,  with  the  water 
stolen  by  the  parasitic  roots  or  haustoria  imbedded  in  the 
wood  of  the  host.     Evidently  the  needed  water  may  just 
as  well  be  taken  from  the  underground  parts  of  the  host 
as  from  the  upper  portions,  and  accordingly  many  half- 
parasites  are  parasitic  on  roots.     This  is  the  case  with 
many  of  the  beautiful  false  foxgloves  (G-erardia),  with  the 
painted-cup  (Castillea),  and  some  species  of  bastard  toad- 
flax ( Oomandra) ;  see  Flora.     Usually  these  root-parasites 
are  not  recognized  by  non-botanical  people  as  parasites  at 

ssa 


PLATE  IX.  —  A  Cottonwood  covered  with  Mistletoe 


PARASITES  337 

all,  but  in  Germany  a  species  common  in  grain  fields  1  and 
the  eyebright,  which  abounds  in  grass  fields,  are  respectively 
known  as  "hunger"  and  " milk-thief,"  from  the  injury 
they  do  to  the  plants  on  which  they  fasten  themselves. 
The  mistletoe  is  a  familiar  example  of  a  half -parasite, 
which  roots  on  branches  (Plate  IX).  Among  the  scanty 
belts  of  cottonwood  trees  along  streams  in  New  Mexico  it 
is  necessary  to  lop  off  the  mistletoe  every  year  to  give  the 
tree  any  chance  to  grow.  Half-parasites  may  be  known 
from  plants  that  are  fully  parasitic  by  having  green  or 
greenish  foliage,  while  complete  parasites  have  no  chloro- 
phyll and  so  are  not  at  all  green. 

406.  Wholly  Parasitic  Seed-Plants.  —  These  are  so  nearly 
destitute  of  the  power  of  assimilation  that  they  must  rob 
other  plants  of  all  needed  food  or  die  of  starvation.    Some, 
like  the  cancer-root  (see  Flora),  are  root-parasites ;  others, 
like  the  dodder,  are  parasitic  on  stems  above  ground.     The 
most  dependent  species  of  all,  such  as  the  flax-dodder,  can 
live  on  only  one  kind  of  host,  while  the  coarse  orange- 
stemmed  dodder,2  which  is  common  all  over  the  central 
and  the  northeastern  states,  grows  freely  on  many  kinds 
of  plants,  from  golden-rods  to  willows. 

407.  Parasitic  Cryptogams.  —  The  wheat  rust  (Sect.  310) 
affords  an  excellent   example   of   the    relations    between 
parasitic  fungi  and  their  hosts.     The  illustration  showing 
the  potato  blight  escaping  from  a  stoma  of  the  potato  leaf 
(Fig.  191)   shows  plainly  one  way  in  which  a  microscopic 
parasite  finds  its  way  out  of  the  tissues  of  the  host-plant 
to  ripen  and  scatter  its  spores. 

1  Alectorolophus  hirsutus. 

2  Cuscuta  Gronovii.  * 


338  FOUNDATIONS   OF  BOTANY 

Perhaps  the  most  interesting,  certainly  to  us  the  most 
practically  important,  cases  of  parasitism  are  those  in 
which  the  bodies  of  animals,  and  especially  of  men,  are 
attacked  by  parasitic  plants.  Bacilli  and  other  bacteria 
of  many  species  (Sect.  263)  are  among  the  commonest 
parasites  which  use  the  bodies  of  animals  as  hosts,  and 
two  or  three  examples  will  serve  to  illustrate  how  they 
find  a  lodgment  in  the  host. 

Rich  garden  soil,  the  dust  of  stables,  and  a  good  many 
other  sources  often  contain  immense  numbers  of  a  bacil- 
lus1 which  causes  lockjaw.  A  man  in  cleaning  harness 
scratches  his  hand  with  a  buckle,  introduces  the  bacilli 
into  his  system,  and  is  soon  taken  with  an  attack  of  lock- 
jaw. Sewage  water  often  swarms  with  the  bacilli  of 
typhoid  fever2  (Fig.  174).  The  people  in  a  city  drink 
unfiltered  water  from  a  river  into  which  sewage  has  been 
allowed  to  run  higher  up  stream,  the  bacilli  multiply  at  a 
rapid  rate  in  the  intestines  of  those  who  have  drunk  the 
water,  and  many  of  them  are  taken  sick  with  typhoid 
fever.  The  phlegm  expectorated  by  consumptive  patients 
is  full  of  the  consumption  bacillus ; 3  this  phlegm  becomes 
dried  up  on  floors,  streets,  or  sidewalks,  it  is  breathed  by 
every  one  in  the  form  of  fine  dust,  and  in  the  lungs  of 
many  who  breathe  it  colonies  of  the  bacillus  are  formed 
and  the  disease  (consumption)  becomes  established  in 
these  persons. 

408.  Enslaved  Plants.  —  Cases  in  which  one  kind  of 
plant  is  useful  in  procuring  food  (or  the  raw  materials 
of  food)  for  another  kind  are  quite  oommon. 

The  relations  on  which  algse  and  fungi  live  together  in 

1  Bacillus  tetani.          *  2  Bacillus  typhi.  8  Bacillus  tuberculosis. 


PARASITES 


339 


the  form  of  lichens  have  already  been  described  (Sect.  331). 
It  is  not  correct  to  describe  the  condition  of  such  algae 
as  slavery  if  the  term  is  meant  to  imply  that  they  derive 
no  benefit  from  the  association.  Perhaps  serfdom  is  a 


—  -t 


t 


FIG.  236.  —  Roots  of  Red  Clover  with  Tubercles. 

/,  sections  of  ascending  branches  ;  6,  enlarged  base  of  stem ;  t,  root-tubercles 
containing  bacteria. 


more  suitable  word,  though  it  is  not  the  term  used  by 
botanists.  At  all  events,  the  alga  is  enclosed  within  a 
network  of  fungus  hyphae  from  which  it  cannot  readily 
escape,  and  there  does  most  of  the  work  of  the  lichen, 
including  all  of  the  manufacture  of  food  from  carbon 
dioxide. 


340 


FOUNDATIONS   OF  BOTANY 


409.  Messmates.1  —  Plants  of  very  diverse  character, 
which  live  most  intimately  together  to  the  advantage  of 
both  parties,  may  be  called  messmates,  since  in  some  fashion 

or  other  they  divide  the 
food  supply  between 
them. 

Bacteria  live  in  col- 
onies enclosed  in  root- 
tubercles  on  the  roots  of 
certain  plants,  for  in- 
stance, beans,  peas,  lu- 
pines, vetches,  and  clover 
(Fig.  236),  and  render 
the  greatest  service  to 
the  plant  to  which  the 
roots  belong,  from  which 
they  also  derive  food  and 
shelter.  Such  plants  do 
not  develop  root- 
tubercles  and  will  not 
grow  well  in  sterilized 
soil,  that  is,  soil  in  which 
the  bacteria  have  been 

FIG.  237.  — Common  Pitcher-Plant.2  killed   by  baking.       It  is 

At  the  right  one  of  the  pitcher-like  leaves  is       foun^   that    the    bacteria 
shown  in  cross-section. 

serve  to  change  nitrogen 

taken  from  the  air  of  the  soil  into  nitric  acid,  which  is  a 

most  important  ingredient  in  the  manufacture  of  proteids. 

Many  trees,  for  example,  oaks,  beeches,  and  the  cone- 

1  This  term  is  borrowed  from  the  zoologists  as  a  much  simpler  one  than 
symbionts  to  express  the  relation  variously  known  as  symbiosis,  commensalism, 
or  mutualism.  2  Sarracenia  purpurea. 


INSECTIVOROUS   PLANTS 


341 


FIG.  238.  —  Sundew  (Drosera  rotundifolia). 

bearing  evergreens,  and  a  considerable  number  of  herbaceous 
plants,  such  as  the  Indian  pipe  (Monotropa,  Plate  V), 
are  covered  with  a  growth  of  fungus  hyphse  (Sect.  307). 


342 


FOUNDATIONS   OF   BOTANY 


FIG.  239.  — Blade  of  Leaf 
of  Sundew.  (Somewhat 
magnified.) 


This  growth  completely  surrounds  the 
young,  active  tips  of  all  the  roots  and 
the  threads  of  the  mykorhiza,  as  it  is 
called,  seem  to  do  the  work  of  root- 
hairs. 

410.  Carnivorous  Plants.  —  In  the 
ordinary  pitcher-plants  (Fig.  237)  the 
leaf  appears  in  the  shape  of  a  more  or 
less  hooded  pitcher.  These  pitchers 
are  usually  partly  filled  with  water, 
and  in  this  water  very  many  drowned 
and  decaying  insects  are  commonly 
to  be  found.  The  insects  have  flown 
or  crawled  into  the  pitcher,  and,  once  inside,  have  been 
unable  to  escape  on  account  of  the  dense  growth  of  bristly 
hairs  about  the  mouth,  all  pointing  inward  and  downward. 
How  much  the  com- 
mon American  pitcher- 
plants  depend  for 
nourishment  on  the 
drowned  insects  in  the 
pitchers  is  not  defi- 
nitely known,  but  it  is 
certain  that  some  of 
the  tropical  species  re- 
quire such  food.1 

In  other  rather  com- 
mon plants,  the  sun- 
dews,  insects  are 


FIG.  240.  — Leaves  of  Sundew.     (Somewhat 

magnified.) 

The  one  at  the  left  has  all  its  tentacles  closed 
over  captured  prey  ;  the  one  at  the  right  has 
only  half  of  them  thus  closed. 


1  Where  the  Sarracenia  is  abundant  it  will  be  found  interesting  and  profit- 
able to  make  a  careful  class  study  of  its  leaves.  See  Geddes,  Chapters  in 
Modern  Botany,  Chapters  I  and  II. 


INSECTIVOROUS   PLANTS 


343 


caught  by  a  sticky  secretion  which  proceeds  from  hairs  on 
the  leaves.     In  one  of  the  commonest  sundews  the  leaves 
consist  of  a  roundish  blade,  borne  on  a  moderately  long 
petiole.     On  the  inner  surface  and  round  the  margin  of 
the  blade  (Fig.  239)  are  borne  a  considerable  number  of 
short   bristles,    each    ter- 
minating in  a  knob  which 
is  covered  with  a  clear, 
sticky  liquid.      When  a 
small  insect  touches  one 
of  the  sticky  knobs,   he 
is  held  fast  and  the  hairs 
at    once    begin    to    close 
over   him,    as    shown   in 
Fig.  240.     Here  he  soon 
dies  and  then  usually  re- 
mains    for    many    days, 
while  the  leaf  pours  out 
a    juice    by    which    the 
soluble  parts  of  the  insect 
are  digested.     The  liquid 
containing    the    digested 
portions  is  then  absorbed 
by  the  leaf  and  contrib- 
utes an  important  part  of  the  nourishment  of  the  plant, 
while  the  undigested  fragments,  such  as  legs,  wing-cases,- 
and  so  on,  remain  on  the  surface  of  the  leaf  or  may  drop 
off  after  the  hairs  let  go  their  hold  on  the  captive  insect. 

In  the  Venus  flytrap,  which  grows  in  the  sandy  regions 
of  eastern  North  Carolina,  the  mechanism  for  catching 
insects  is  still  more  remarkable.  The  leaves,  as  shown  in 


FIG.  241.  —  Venus  Flytrap. 


344  FOUNDATIONS   OF  BOTANY 

Fig.  241,  terminate  in  a  hinged  portion  which  is  surrounded 
by  a  fringe  of  stiff  bristles.  On  the  inside  of  each  half 
of  the  trap  grow  three  short  hairs.  The  trap  is  so  sensi- 
tive that  when  these  hairs  are  touched  it  closes  with  a  jerk 
and  very  generally  succeeds  in  capturing  the  fly  or  other 
insect  which  has  sprung  it.  The  imprisoned  insect  then 
dies  and  is  digested,  somewhat  as  in  the  case  of  those 
caught  by  the  sundew,  after  which  the  trap  reopens  and 
is  ready  for  fresh  captures. 

411.  Object  of  catching  Animal  Food. — It  is  easy  to 
understand  why  a  good  many  kinds  of  plants  have  taken 
to  catching  insects  and  absorbing  the  digested  products. 
Carnivorous,  or  flesh-eating,  plants  belong  usually  to  one 
of  two  classes  as  regards  their  place  of  growth  ;  they  are 
bog-plants  or  air-plants.  In  either  case  their  roots  find  it 
difficult  to  secure  much  nitrogen-containing  food,  that  is, 
much  food  out  of  which  proteid  material  can  be  built  up. 
Animal  food,  being  itself  largely  proteid,  is  admirably 
adapted  to  nourish  the  growing  parts  of  plants,  and  those 
which  could  develop  insect-catching  powers  would  stand 
a  far  better  chance  to  exist  as  air-plants  or  in  the  thin, 
watery  soil  of  bogs  than  plants  which  had  acquired  no 
such  resources. 


CHAPTER   XXVII 
HOW   PLANTS    PROTECT    THEMSELVES    FROM   ANIMALS 

412.  Destruction  by  Animals.  —  All  animals  are  sup- 
ported directly  or  indirectly  by  plants.     In  some  cases  the 
animal  secures  its  food  without  much  damaging  the  plant 
on  which  it  feeds.     Browsing  on  the  lower  branches  of  a 
tree  may  do  it  little  injury,  and  grazing  animals,  if  not 
numerous,  may  not  seriously  harm  the  pasture  on  which 
they  feed.     Fruit-eating  animals   may  -even  be  of  much 
service  by  dispersing  seeds  (Sect.  458).     But  seed-eating 
birds  and  quadrupeds,  animals  which,  like  the  hog,  dig  up 
fleshy  roots,  rootstocks,   tubers  or   bulbs,  and  eat  them, 
or  animals  which,  like  the  sheep,  graze  so  closely  as  to 
expose  the  roots  of  grasses  or  even  of  forest  trees  to  be 
parched  by  the  sun,  destroy  immense  numbers  of  plants. 
So  too  with  wood-boring  and  leaf-eating  insects,  and  snails, 
which  consume  great  quantities  of  leaves. 

413.  Some  Modes  of  Protection  from  Animals.  —  Many 
of  the  characteristics  of  plants  may  be  wholly  or  partly 
due  to  adaptations  for  protective  purposes,  while  in  par- 
ticular cases  we  cannot  be  sure  of  the  fact.     Perching  on 
lofty  rocks  or  on  branches  of  trees,  burying  the  perennial 
part  (bulb,  rootstock,  etc.)  underground,  growing  in  dense 
masses,  like  a  canebrake  or  a  thicket  of  blackberry  bushes  ; 
all  such  habits  of  plants  may  be  partly  or  altogether  val- 
uable to  the  plant  as  means  of  avoiding  the  attacks  of 
animals,  but  this  cannot  be  proved.     On  the  other  hand, 

345 


346  FOUNDATIONS   OF  BOTANY 

there  are  plenty  of  instances  of  structures,  habits,  or  accu- 
mulations of  stored  material  in  their  tissue  which  plants 
seem  to  have  acquired  mainly  or  entirely  as  means  of 
defense.  Some  of  the  most  important  are: 

(1)  The  habit  of  keeping  a  bodyguard  of  ants. 

(2)  Mimicking  the  appearance  of  dangerous  or  uneatable  plants,  or 

imitating  pebbles  or  earth,  so  that  they  may  be  overlooked. 

(3)  Forming   tough,   corky,  woody,    limy   or  flinty   and   therefore 

nearly  uneatable  tissue. 

(4)  Arming  exposed  parts  with  cutting  edges,  sharp  or  stinging 

hairs,  prickles,  or  thorns. 

(5)  Accumulating  unpleasant  or  poisonous  substances  in  exposed 

parts. 

414,-  Ant-Plants.  —  Some  ants  live  on  vegetable  food, 
but  most  of  them  eat  only  animal  food,  and  these  latter 
are  extremely  voracious.  It  has  been  estimated  by  a 
careful  scientist,  an  authority  on  this  subject,  that  the 
ants  of  a  single  nest  sometimes  destroy  as  many  as  one 
hundred  thousand  insects  in  a  day.  The  Chinese  orange- 
growers  in  the  Province  of  Canton  have  found  how  useful 
ants  may  be  as  destroyers  of  other  insects,  and  so  they 
place  ant  nests  in  the  orange  trees  and  extend  bamboos 
across  from  one  tree  to  another,  to  serve  as  bridges  for  the 
ants  to  travel  on. 

Certain  tropical  trees,  in  order  to  insure  protection  by 
ants,  offer  them  especial  inducements  to  establish  colonies 
on  their  trunks  and  branches.  The  attractions  which  are 
offered  to  ants  by  various  kinds  of  trees  differ  greatly. 
One  of  the  most  interesting  adaptations  is  that  of  an 
acacia1  (Fig.  242),  which  furnishes  little  growths  at  the 
ends  of  the  leaflets  which  serve  as  ant  food.  These  little 

1  A.  sphaerocephala. 


HOW  PLANTS  PROTECT  THEMSELVES 


347 


growths  are  known  from  their  discoverer  as  Belt's  bodies. 
The  ants  bore  holes  into  the  large  hollow  stipular  thorns 
shown  in  the  figure,  live  in  these  thorns,  feed  on  the 
Belt's  bodies,  and  protect  the  acacia  from  insect  and  other 
enemies.  A  nectary  on  the  leaf  furnishes  additional  food 
to  the  ant  inhabitants  of  the  tree.  A  great  multitude  of 
plants,  some  of  them  herbs,  offer  more  or  less  important 


leaflet 


PIG.  242.  —  An  Ant-Plant  (Acacia). 
t,  thorns  ;  h,  hole  in  thorn  ;  n,  nectary  ;  b,  Belt's  body  on  tip  of  leaflet. 

inducements  to  attract  ant  visitors  ;  the  species  which  are 
known  to  do  this  number  over  three  thousand. 

415.  Plants  which  mimic  Plants  or  Other  Objects.  — 
Instances  of  mimicry  of  protected  plants  by  unprotected 
species  are  not  very  common.  One  of  the  best-known 
cases  is  that  of  the  dead-nettle,  which  is  so  called  because 
it  looks  like  the  stinging  nettle,  though  it  is  perfectly 
harmless.  Some  South  African  plants  (Kleinias)  appear 
to  mimic  pebbles.  Certain  Mesembryanthemums  of  the 


348 


FOUNDATIONS    OF   BOTANY 


same  region  can  hardly  be  distinguished  from  the  earth  in 
which  they  grow. 

416.  Plants  of  Uneatable  Texture.  —  Whenever  tender 
and  juicy  herbage  is  to  be  had,  plants  of  hard  and  stringy 
texture  are  left  untouched.  The  flinty-stemmed  scouring- 
rushes  (Equisetum,  Sect.  361)  and  the  dry,  tough  rushes 
are  familiar  examples  of  uneatable  plants  of  damp  soil. 
In  pastures  there  grow  such  peren- 
nials as  the  bracken  fern  and  the 
hardback  of  New  England  and  the 
iron  weed  and  vervains  of  the  Cen- 
tral States,  which  are  so  harsh  and 
woody  that  the  hungriest  browsing 


FIG.  243.  —  Spiny  Leaves  of  Barberry. 

animal  is  rarely,  if  ever,  seen  to  molest  them.  Still  other 
plants,  like  the  knotgrass  and  cinquefoil  of  our  dooryards, 
are  doubly  safe,  from  their  growing  so  close  to  the  ground 
as  to  be  hard  to  graze  and  from  their  woody  and  unpala- 
table nature.  The  date-palm  (which  can  easily  be  raised 
from  the  seed  in  the  schoolroom  or  the  laboratory)  is  an 
excellent  instance  of  the  same  uneatable  quality,  found 
in  a  tropical  or  sub-tropical  plant. 


HOW  PLANTS  PROTECT  THEMSELVES 


349 


417.  Plants  with  Weapons  for  Defense.1  —  Multitudes 
of  plants,  which  might  otherwise  have  been  subject  to  the 
attacks   of  grazing   or  browsing  animals,  have   acquired 
what  have  with  reason  been  called  weapons.     Shrubs  and 
trees    not   infrequently  produce    sharp-pointed   branches, 
familiar  in  our  own  crab-apple,  wild  plum,  thorn  trees, 
and  above  all  in  the  honey  locust  (Fig.  34),  whose  formida- 
ble thorns  often  branch  in 

a  very  complicated  man- 
ner. 

Thorns,  which  are 
really  modified  leaves,  are 
very  perfectly  exempli- 
fied in  the  barberry  (Fig. 
243).  It  is  much  com- 
moner to  find  the  leaf 
extending  its  midrib  or 
its  veins  out  into  spiny 
points,  as  the  thistle  does,  or  bearing  spines  or  prickles  on 
its  midrib,  as  is  the  case  with  the  nightshade  shown  in  Fig. 
244,  and  with  so  many  roses.  Prickles,  which  are  merely 
hard,  sharp-pointed  projections  from  the  epidermis,  are  of 
too  common  occurrence  to  need  illustration. 

Stipules  are  not  infrequently  found  occurring  as  thorns, 
and  in  our  common  locust  (Fig.  246)  the  bud,  or  the  very 
young  shoot  which  proceeds  from  it,  is  admirably  pro- 
tected by  the  jutting  thorn  on  either  side. 

418.  Pointed,   Barbed,   and   Stinging   Hairs.  —  Needle- 
pointed  hairs  are  an  efficient  defensive  weapon  of  many 
plants.     Sometimes  these  hairs  are  roughened,  like  those 

1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  I,  p.  430. 


FIG.  244.  —  Leaf  of  a  Night- 
shade (Solatium  atropur- 
pureurri). 


350 


FOUNDATIONS   OF   BOTANY 


of  the  bugloss  (Fig.  247,  b) ;  sometimes  they  are  decidedly 
barbed.  If  the  barbs  are  well  developed  they  may  cause 
the  hairs  to  travel  far  into  the  flesh  of  animals  and  cause 
intense  pain.  In  the  nettle  (Fig.  247,  a)  the  hairs  are 
efficient  stings,  with  a  brittle  tip,  which  on  breaking  off 


FIG.  246.  —  Thorn 
Stipules  of  Locust. 


FIG.  245.  —  Euphorbia  splendens. 

The  spines  are  dead  and  dry 

stipules. 

exposes  a  sharp,  jagged 
tube    full    of    irritating 

fluid.     These    tubular    hairs, 

with  their  poisonous  contents, 

will  be  found  sticking  in  the 

skin  of  the  hand  or  the  face 
after  incautious  contact  with  nettles,  and  the  violent  itching 
which  follows  is  only  too  familiar  to  most  people. 

419.  Cutting  Leaves.  —  Some  grasses  and  sedges  are 
generally  avoided  by  cattle  because  of  the  sharp-cutting 
edges  of  their  leaves,  which  will  readily  slit  the  skin  of 
one's  hand  if  they  are  drawn  rapidly  through  the  fingers. 
Under  the  microscope  the  margins  of  such  leaves  are  seen 
to  be  regularly  and  thickly  set  with  sharp  teeth  like  those 
of  a  saw  (Fig.  247,  c,  d). 


HOW  PLANTS  PROTECT  THEMSELVES 


351 


420.  Weapons  of  Desert  Plants.  —  In  temperate  regions, 
where  vegetation  is  usually  abundant,  such,  moderate 
means  of  protection  as  have  just  been  described  are  gener- 
ally sufficient  to  insure  the  safety  of  the  plants  which  have 
developed  them.  But  in  desert  or  semi-desert  regions  the 


FIG.  247.  —  Stinging  Hairs  and  Cutting  Leaves.    (All  much  magnified.) 

a,  stinging  hairs  on  leaf  of  nettle  ;  b,  bristle  of  the  bugloss  ;  c,  barbed  margin 

of  a  leaf  of  sedge ;  d,  barbed  margin  of  a  leaf  of  grass. 

extreme  scarcity  of  plant  life  exposes  the  few  plants  that 
occur  there  to  the  attacks  of  all  the  herbivorous  animals 
that  may  encounter  them.  Accordingly,  great  numbers  of 
desert  plants  are  characterized  by  nauseating  or  poisonous 
qualities  or  by  the  presence  of  astonishingly  developed 
thorns,  while  some  combine  both  of  these  means  of  defense. 


352  FOUNDATIONS   OF  BOTANY 

421.  Offensive  or  Poisonous  Plants.  —  A  disgusting  smell 
is  one  of  the  common  safeguards  which  keep  plants  from 
being  eaten.  The  dog  fennel  (Fig.  227),  the  hound's-tongue 
(Cynoglossum),  the  Martynia,  and  the  tomato-plant  are 
common  examples  of  rank-smelling  plants  which  are  offen- 
sive to  most  grazing  animals  and  so  are  let  alone  by  them. 
Oftentimes,  as  in  the  case  of  the  jimson  weed  (Datura), 
the  tobacco-plant,  and  the  poison  hemlock  (Conium),  the 
smell  serves  as  a  warning  of  the  poisonous  nature  of  the 
plant. 

A  bitter,  nauseating,  or  biting  taste  protects  many  plants 
from  destruction  by  animals.  Buckeye,  horse-chestnut, 
and  maple  twigs  and  leaves  are  so  bitter  that  browsing 
animals  and  most  insects  let  them  alone.  Tansy,  ragweed, 
boneset,  southernwood,  and  wormwood  are  safe  for  the 
same  reason.  The  nauseous  taste  of  many  kinds  of  leaves 
and  stems,  such  as  those  of  the  potato,  and  the  fiery  taste 
of  pepper-corns,  red  peppers,  mustard,  and  horse-radish, 
make  these  substances  uneatable  for  most  animals.  Prob- 
ably both  the  smell  and  the  taste  of  onions  serve  to  insure 
the  safety  of  the  bulbs  from  the  attacks  of  most  grubs, 
and  the  hard  corm  of  the  jack-in-the-pulpit  (Ariscema) 
(Frontispiece)  is  carefully  let  alone  on  account  of  the 
blistering  nature  of  its  contents. 

Poisonous  plants  are  usually  shunned  by  grown-up 
animals,  though  the  young  ones  will  sometimes  eat  such 
plants  and  may  be  killed  by  them.  Almost  any  part  of  a 
poisonous  species  may  contain  the  poison  characteristic  of 
the  plant,  but,  for  obvious  reasons,  such  substances  are 
especially  apt  to  be  stored  in  the  parts  of  the  plant  where 
its  supply  of  reserve  food  is  kept. 


CHAPTER   XXVIII 
ECOLOGY   OF  FLOWERS 

422.  Topics  of  the  Chapter.  —  The  ecology  of  flowers  is 
concerned  mainly  with  the  means  by  which  the  transfer- 
ence of  pollen  or  pollination  is  effected,  and  with  the  ways 
in  which  pollen   is    kept   away  from  undesirable    insect 
visitors  and  from  rain. 

423,  Cross-Pollination    and    Self -Pollination.  —  It    was 
long  supposed  by  botanists  that  the  pollen  of  any  perfect 
flower  needed  only  to  be  placed  on  the  stigma  of  the  same 
flower   to  insure  satisfactory  fertilization.     But  in    1857 
and  1858  the  great  English  naturalist,  Charles  Darwin, 
stated  that  certain  kinds  of  flowers  were  entirely  dependent 
for  fertilization  on  the  transference  of  pollen  from  one 
plant  to  another,  and  he  and  other  botanists  soon  extended 
the  list  of  such  flowers  until  it  came  to  include  most  of 
the  showy,  sweet-scented,  or  otherwise  conspicuous  kinds. 
It    was    also    shown   that  probably   nearly  all   attractive 
flowers,  even  if  they  can  produce  some  seed  when  self- 
pollinated,  do  far  better  when  pollinated  from  the  flowers 
of  another  plant  of  the  same  kind.1     This  important  fact 
was  established  by  a  long  series  of  experiments  on  the 
number  and  vitality  of  seeds  produced  by  a  flower  when 
treated  with  its  own  pollen,  or  self-pollinated,  and  when 

1  See  Darwin's  Cross  and  Self-Fertilization  in  the    Vegetable  Kingdom 
(especially  Chapters  I  and  II). 

353 


354  FOUNDATIONS   OF  BOTANY 

treated  with  pollen  from  another  flower  of  the  same  kind, 
or  cross-pollinated.1 

424.  Wind-Pollinated  Flowers.2  —  It  has  already  been 
mentioned  that  some  pollen  is  dry  and  powdery,  and 
other  kinds  are  more  or  less  sticky.  Pollen  of  the  dusty 
sort  is  light,  and  therefore  adapted  to  be  blown  about 
by  the  wind.  Any  one  who  has  been  much  in  corn- 
fields after  the  corn  has  "  tasseled  "  has  noticed  the  pale 
yellow  dusty  pollen  which  flies  about  when  a  cornstalk  is 
jostled,  and  which  collects  in  considerable  quantities  on 
the  blades  of  the  leaves.  Corn  is 
monoecious,  but  fertilization  is  best 
accomplished  by  pollen  blown  from 
the  "tassel"  (stamens)  of  one  plant 

FIG.  M8.-Ptatil  of  a  Grass,     b   •  •    d  ^  ^     u    ^  „  (pistils) 

provided  with  a  Feathery 

stigma,  adapted  for  wind-    of    another    plant.       This    is    well 
shown  by  the  fact,  familiar  to  every 

observing  farmer's  boy,  that  solitary  cornstalks,  such  as 
often  grow  very  luxuriantly  in  an  unused  barnyard  or 
similar  locality,  bear  very  imperfect  ears  or  none  at 
all.  The  common  ragweed,  another  monoecious  plant, 
is  remarkable  for  the  great  quantities  of  pollen  which 
shake  off  it  on  to  the  shoes  or  clothes  of  the  passer-by, 
and  it  is  wind-pollinated.  So,  too,  are  the  monoecious 
pines,  and  these  produce  so  much  pollen  that  it  has  been 
mistaken  for  showers  of  sulphur,  falling  often  at  long  dis- 
tances from  the  woods  where  it  was  produced.  The  pistil 
of  wind-pollinated  flowers  is  often  feathery  and  thus 
adapted  to  catch  flying  pollen-grains  (Fig.  248).  Other 

1  On  dispersion  of  pollen  see  Kerner  and  Oliver,  Vol.  II,  pp.  129-287. 

2  See  Miss  Newell's  Botany  Reader,  Part  II,  Chapter  VII. 


ECOLOGY   OF  FLOWERS  355 

characteristics  of  such  flowers  are  the  inconspicuous  char- 
acter of  their  perianth,  which  is  usually  green  or  greenish, 
the  absence  of  odor  and  of  nectar,  the  regularity  of  the 
corolla,  and  the  appearance  of  the  flowers  before  the  leaves 
or  their  occurrence  on  stalks  raised  above  the  leaves. 

Pollen  is,  in  the  case  of  a  few  aquatic  plants,  carried 
from  flower  to  flower  by  the  water  on  which  it  floats. 

425.  Insect-Pollinated  Flowers.  —  Most    plants    which 
require  cross-pollination  depend  upon  insects    as  pollen- 
carriers,1  and  it  may  be  stated  as  a  general  fact  that  the 
showy  colors  and  markings  of  flowers  and  their  odors  all 
serve  as  so  many  advertisements  of  the  nectar  (commonly 
but  wrongly  called  honey)   or  of  the   nourishing  pollen 
which  the  flower  has  to  offer  to  insect  visitors. 

Many  insects  depend  mainly  or  wholly  upon  the  nectar 
and  the  pollen  of  flowers  for  their  food.  Such  insects 
usually  visit  during  any  given  trip  only  one  kind  of  flower, 
and  therefore  carry  but  one  kind  of  pollen.  Going  straight 
from  one  flower  to  another  with  this,  they  evidently  waste 
far  less  pollen  than  the  wind  or  water  must  waste.  It  is 
therefore  clearly  advantageous  to  flowers  to  develop  such 
adaptations  as  fit  them  to  attract  insect  visitors,  and  to 
give  pollen  to  the  latter  and  receive  it  from  them. 

426.  Pollen-Carrying  Apparatus  of  Insects.2 — Ants  and 
some  beetles  which  visit  flowers  have  smooth  bodies,  to 
which  little  pollen  adheres,  so  that  their  visits  are  often  of 
slight  value  to  the  flower,  but  many  beetles,  all  butterflies 
and  moths,  and  most  bees  have   bodies   roughened  with 
scales  or  hairs  which  hold  a  good  deal  of  pollen  entangled. 

1  A  few  are  pollinated  by  snails ;  many  more  by  humming-birds  and  other 
birds.  2  gee  Muller's  Fertilization  of  Flowers,  Part  II. 


356 


FOUNDATIONS    OF   BOTANY 


In  the  common  honey-bee  (and  in  many  other  kinds)  the 
greater  part  of  the  insect  is  hairy,  and  there  are  special 
collecting  baskets,  formed  by  bristle-like  hairs,  on  the  hind 

legs  (Fig.  249).  It  is  easy 
to  see  the  load  of  pollen 
accumulated  in  these  bas- 
kets after  such  a  bee  has 
visited  several  flowers.  Of 
course  the  pollen  which  the 
bee  packs  in  the  baskets  and 
carries  off  to  the  hive,  to  be 
stored  for  food,  is  of  no  use 
in  pollination.  In  fact  such 
FIG.  249.  pollen  is  in  one  sense  entirely 

A,  right  hind  leg  of  a  honey-bee  (seen  from     wasted.          But     since      Such 
behind  and  within)  ;   J3,  the   tibia,  ti, 
seen  from  the  outside,  showing  the  col-     bees    as    have    these     Collect- 


lecting  basket  formed  of  stiff  hairs. 


are     the 


industrious  visitors  to  flowers,  they  accomplish  an  immense 
share  of  the  work  of  pollination  by  means  of  the  pollen 
grains  which  stick  to  their  hairy  coats  and  are  then  trans- 
ferred to  other  flowers  of  the  same  kind  next  visited  by 
the  bee. 

427,  Nectar  and  Nectaries.  —  Nectar  is  a  sweet  liquid 
which  flowers  secrete  for  the  purpose  of  attracting  insects. 
After  partial  digestion  in  the  crop  of  the  bee,  nectar 
becomes  honey.  Those  flowers  which  secrete  nectar  do 
so  by  means  of  nectar  glands,  small  organs  whose  structure 
is  something  like  that  of  the  stigma,  situated  often  near 
the  base  of  the  flower,  as  shown  in  Fig.  250.  Sometimes 
the  nectar  clings  in  droplets  to  the  surface  of  the  nectar 
glands  ;  sometimes  it  is  stored  in  little  cavities  or  pouches 


ECOLOGY   OF   FLOWERS 


357 


called  nectaries.     The  pouches  at  the  bases  of  columbine 
petals  are  among  the  most  familiar  of  nectaries. 

428.  Odors  of  Flowers.  —  The  acuteness  of  the  sense  of 
smell  among  insects  is  a  familiar  fact.     Flies  buzz  about 
the  wire  netting  which  covers  a  piece  of  fresh  meat  or  a 
dish  of   syrup,  and  bees,  wasps,  and  hornets  will  fairly 
besiege  the  window  screens  of  a  kitchen  where  preserving 
is  going  on.     Many  plants  find  it  possible  to  attract  as 
many  insect  visitors  as  they  need  without  giving  off  any 
scent,  but  small  flowers,  like  the  mignonette,  and  night- 
blooming  ones,   like  the  white   tobacco  and  the  evening 
primrose,  are  sweet-scented  to  attract  night-flying  moths. 
It  is  interesting  to  observe  that  the  majority  of  the  flowers 
which  bloom  at  night  are  white,  and  that  they  are  much 
more   generally  sweet-scented  than  flowers  which  bloom 
during  the   day.     A  few  flowers  are 
carrion-scented  (and  purplish  or  brown- 
ish colored)  and  attract  flies. 

429.  Colors  of    Flowers.  —  Flowers 
which  are  of  any  other  color  than  green 
probably  in  most  cases   display  their 
colors  to  attract  insects,  or  occasionally 
birds.  The  principal  color  of  the  flower 
is  most  frequently  due  to  showy  petals; 
sometimes,  as  in  the  marsh  marigold,  it 
belongs  to  the  sepals;  and  not  infre- 
quently, as  in  some  cornels  and  Eu- 
phorbias (Fig.  245),  the  involucre   is  more  brilliant  and 
conspicuous  than  any  part  of  the  flower  strictly  so  called. 

Different    kinds    of    insects    appear   to   be    especially 
attracted  by  different  colors.      In    general,   dull    yellow, 


FIG.  250.  —  Stamens  and 
Pistil  of  the  Grape 
(magnified),  with  a 
Nectar  Gland,  g,  be- 
tween Each  Pair  of 
Stamens. 


358  FOUNDATIONS   OF  BOTANY 

brownish,  or  dark  purple  flowers,  especially  if  small,  seem 
to  depend  largely  on  the  visits  of  flies.  Red,  violet,  and 
blue  are  the  colors  by  which  bees  and  butterflies  are  most 
readily  enticed.  The  power  of  bees  to  distinguish  colors 
has  been  shown  by  a  most  interesting  set  of  experiments 
in  which  daubs  of  honey  were  put  on  slips  of  glass  laid  on 
separate  pieces  of  paper,  each  of  a  different  color,  and 
exposed  where  bees  would  find  them.1 

It  is  certain,  however,  that  colors  are  less  important 
means  of  attraction  than  odors  from  the  fact  that  insects 
are  extremely  near-sighted.  Butterflies  and  moths  cannot 
see  distinctly  at  a  distance  of  more  than  about  five  feet, 
bees  and  wasps  at  more  than  two  feet,  and  flies  at  more 
than  two  and  a  fourth  feet.  Probably  no  insects  can  make 
out  objects  clearly  more  than  six  feet  away.2  Yet  it  is 
quite  possible  that  their  attention  is  attracted  by  colors  at 
distances  greater  than  those  mentioned. 

430.  Nectar  Guides.  —  In  a  large  number  of  cases  the 
petals  of  flowers  show  decided  stripes  or  rows  of  spots,  of 
a  color  different  from  that  of  most  of  the  petal.     These 
commonly  lead  toward  the  nectaries,  and  it  is  possible  that 
such  markings  point  out  to  insect  visitors  the  way  to  the 
nectaries.     Following   this    course,   the    insect   not   only 
secures  the  nectar  which  he  seeks,  but  probably  leaves 
pollen  on  the  stigma  and  becomes  dusted  with  new  pollen, 
which  he  carries  to  another  flower. 

431.  Facilities  for  Insect  Visits.  —  Regular  polypetalous 
flowers  have  no  special  adaptations  to  make  them  singly 

1  See  Lubbock's  Flowers,  Fruits,  and  Leaves,  Chapter  1.     On  the  general 
subject  of  colors  and  odors  in  relation  to  insects,  see  Miiller's  Fertilization  of 
Flowers,  Part  IV. 

2  See  Packard's  Text-Book  of  Entomology,  p.  260. 


ECOLOGY   OF   FLOWERS 


359 


accessible  to  insects,  but  they  lie  open  to  all  comers. 
They  do,  however,  make  themselves  much  more  attractive 
and  afford  especial  inducements  in  the  matter  of  saving 
time  to  flower-frequenting  insects  by  being  grouped.  This 
purpose  is  undoubtedly  served  by  dense  flower-clusters, 
especially  by  heads  like  those  of  the  clovers  and  by  the 
peculiar  form  of  head  found  in  so-called  composite  flowers, 
like  the  sunflower,  the  bachelor's  button,  and  the  yarrow 
(Fig.  133).  In  many  such  clusters  the  flowers  are  special- 
ized, some  carrying  a  showy  strap- 
shaped  corolla,  to  serve  as  an 
advertisement  of  the  nectar  and 
pollen  contained  in  the  inconspicu- 
ous tubular  flowers  (see  Plate  XI). 
Irregular  flowers  probably  always 
are  more  or  less  adapted  to  par- 
ticular insect  (or  other)  visitors. 
The  adaptations  are  extremely  nu- 
merous ;  —  here  only  a  very  few  of 
the  simpler  ones  will  be  pointed 
out.  Where  there  is-  a  drooping 
lower  petal  (or,  in  the  case  of  a  gamopetalous  corolla,  a 
lower  lip),  this  serves  as  a  perch  upon  which  flying  insects 
may  alight  and  stand  while  they  explore  the  flower,  as  the 
beetle  is  doing  in  Fig.  251.  In  Fig.  252  one  bumblebee 
stands  with  his  legs  partially  encircling  the  lower  lip  of 
the  dead-nettle  flower,  while  another  perches  on  the  sort 
of  grating  made  by  the  stamens  of  the  horse-chestnut 
flower.  The  honey-bee  entering  the  violet  clings  to  the 
beautifully  bearded  portion  of  the  two  lateral  petals,  while 
it  sucks  the  nectar  from  the  spur  beneath. 


FIG.  251. —A  Beetle  on  the 

Flower  of  the  Twayblade. 

(Enlarged  three  times.) 


360 


FOUNDATIONS   OF   BOTANY 


432.  Protection  of  Pollen  from  Unwelcome  Visitors.  —  It 
is  usually  desirable  for  the  flower  to  prevent  the  entrance 
of  small  creeping  insects,  such  as  ants,  which  carry  little 
pollen  and  eat  a  relatively  large  amount  of  it.  The  means 
adopted  to  secure  this  result  are  many  and  curious.  In 


FIG.  252.  —  Bees  visiting  Flowers. 

At  the  left  a  bumblebee  on  the  flower  of  the  dead  nettle  ;  below  a  similar 
bee  in  the  flower  of  the  horse-chestnut ;  above  a  honey-bee  in  the  flower 
of  a  violet. 

some  plants,  as  the  common  catchfly,  there  is  a  sticky 
ring  about  the  peduncle,  some  distance  below  the  flowers, 
and  this  forms  an  effectual  barrier  against  ants  and  like 
insects.  Very  frequently  the  calyx  tube  is  covered  with 
hairs,  which  are  sometimes  sticky.  How  these  thickets 
of  hairs  may  appear  to  a  very  small  insect  can  perhaps 
be  more  easily  realized  by  looking  at  the  considerably 


ECOLOGY   OF   FLOWERS  361 

magnified  view  of   the   hairs  from  the   outer  surface  of 
mullein  petals,  shown  in  Fig.  25 3. 1 

Sometimes  the  recurved  petals  or  divisions  of  the  corolla 
stand  in  the  way  of.  creeping  insects.     In  other  cases  the 


FIG.  253.  —  Branching  Hairs  from  the  Outside  of  the  Corolla  of  the  Common 
Mullein.    (Magnified.)    dr,  a  gland. 


FIG.  254.  — A  Sphinx  Moth,  with  a  Long  Sucking-Tube. 

throat  of  the  corolla  is  much  narrowed  or  closed  by  hairs, 
or  by  appendages.     Those  flowers  which  have  one  or  more 

1  On  protection  of  pollen,  see  Kerner  and  Oliver,  Vol.  II,  pp.  95-109. 

- 


362  FOUNDATIONS   OF   BOTANY 

sepals  or  petals  prolonged  into  spurs,  like  the  nasturtium 
and  the  columbine,  are  inaccessible  to  most  insects  except 
those  which  have  a  tongue  or  a  sucking-tube  long  enough 
to  reach  to  the  nectary  at  the  bottom  of  the  spur.  The 
large  sphinx  moth,  shown  in  Fig.  254,  which  is  a  common 
visitor  to  the  flowers  of  the  evening  primrose,  is  an 
example  of  an  insect  especially  adapted  to  reach  deep  into 
long  tubular  flowers. 

A  little   search  among  flowers,  such   as  those   of  the 
columbine   or  the  foxglove,   will  usually  disclose   many 
which  have  had  the  corolla  bitten  through  by  bees,  which 
are  unable  to  get  at  the  nectar  by  fair  means  or  unwilling . 
to  take  the  trouble  to  do  so ;  and  they  therefore  steal  it. 

433.  Bird-Pollinated  Flowers.  —  Some  flowers  with  very 
long  tubular  corollas  depend  entirely  upon  birds  to  carry 
their  pollen  for  them.     Among  garden  flowers  the  gladi- 
olus, the  scarlet  salvia,  and  the  trumpet  honeysuckle  are 
largely  dependent  upon  humming-birds  for  their  pollination. 
The  wild  balsam  or  jewel-weed  and  the  trumpet-creeper 
(Plate  X)  are  also  favorite  flowers  of  the  humming-bird. 

434.  Prevention  of  Self -Fertilization.  —  Dioecious  flowers 
are  of  course  quite  incapable  of  self-pollination.    Pistillate 
monoecious  flowers  may  be  pollinated  by  staminate  ones 
on  the  same  plant,  but  this  does  not  secure  as  good  seed 
as  is  secured  by  having  pollen  brought  to  the  pistil  from 
a  different  plant  of  the  same  kind. 

In  perfect  flowers  self-pollination  would  commonly  occur 
unless  it  were  prevented  by  the  action  of  the  essential 
organs  or  by  something  in  the  structure  of  the  flower.  In 
reality  many  flowers  which  at  first  sight  would  appear  to 
be  designed  to  secure  self-pollination  are  almost  or  quite 


O 


ECOLOGY   OF  FLOWERS 


363 


incapable  of  it.  Frequently  the  pollen  from  another  plant 
of  the  same  species  prevails  over  that  which  the  flower 
may  shed  on  its  own  pistil,  so  that  when  both  kinds  are 
placed  on  the  stigma  at  the  same  time  it  is  the  foreign 
pollen  which  causes  fertilization.  But  apart  from  this 
fact  there  are  several  means  of  insuring  the  presence  of 
foreign  pollen,  and  only  that,  upon  the  stigma,  just  when 
it  is  mature  enough  to 
receive  pollen  tubes. 

435.  Stamens  and  Pistils 
maturing  at  Different 
Times.  —  If  the  stamens 
mature  at  a  different  time 
from  the  pistils,  self-polli- 


nation is.  as  effectually  pre- 
vented as  though  the  plant 
were  dioecious.  This  un- 
equal maturing  or  dichog- 
amy occurs  in  many  kinds 

Of    flowers.       In    SOme,    the 

0 

fig  WOrt     and     the     Common    In  A  (earlier  stage)  the  stamens  are  mature, 

while  the  pistil  is  stm  undevel°Ped  and  bent 

to  one  side.  In  B  (later  stage)  the  stamens 
have  withered  and  the  stigmas  have  sepa- 
rated,  ready  for  the  reception  of  pollen. 


255'  -™°™  '<*  Cterodendronin  Two 


plantain  for  example,  the 

pistil    develops    before    the 

•i  TT         ., 

stamens,  but  usually  the 
reverse  is  the  case.  The  Clerodendron,1  a  tropical  African 
flower  (Fig.  255),  illustrates  in  a  most  striking  way  the 
development  of  stamens  before  the  pistil.  The  insect  visitor, 
on  its  way  to  the  nectary,  can  hardly  fail  to  brush  against 
the  protruding  stamens  of  the  flower  in  its  earlier  stage 
(at  J.),  but  it  cannot  deposit  any  pollen  on  the  stigmas, 

1  C.  Thompsoniae. 


364 


FOUNDATIONS   OF  BOTANY 


which  are  unripe,  shut  together,  and  tucked  aside  out  of 
reach.  On  flying  to  a  flower  in  the  later  stage  the  pollen 
just  acquired  will  be  lodged  on  the  prominent  stigmas  and 
thus  produce  the  desired  cross-pollination. 


--sag 


I  II  III  IV 

FIG.  256.  —  Provisions  for  Cross-Pollination  in  the  High  Mallow. 

I,  essential  organs  as  found  in  the  bud  ;  II,  same  in  the  staminate  stage,  the 
anthers  discharging  pollen,  pistils  immature ;  III,  intermediate  stage, 
slig,  the  united  stigmas ;  IV,  pistillate  stage,  the  stigmas  separated, 
stamens  withered. 

Closely  related  flowers  often  differ  in  their  plan  of 
pollination.  The  high  mallow,  a  plant  cultivated  for  its 
purplish  flowers,  which  has  run  wild  to  some  extent,  is 
admirably  adapted  to  secure  cross-pollination,  since  when 
its  stamens  are  shedding  pollen,  as  in 
Fig.  256,  II,  the  pistils  are  incapable  of 
receiving  it,  while  when  the  pistils  are 
mature,  as  at  IV,  the  stamens  are  quite 
withered.  In  the  common  low  mallow 
of  our  dooryards  and  waysides  insect 
pollination  may  occur,  but  if  it  does  not 

FIG.  257.  — Stamens     *' 

and  Pistils  of  Round-    the  curling  stigmas  finally  come  in  con- 
Leafed  Maiiow.  The    il(ici   ^fa   ih&    projectmg    stamens    and 

stignvas  curled  round 

among  the  stamens    receive  pollen  from  them,  as  is  indicated 

to  admit  of  self-pol-      .        T-,.        ctrn 
lination.  "1    tig.   257. 


ECOLOGY   OF   FLOWERS 


365 


436.    Movements  of  Floral  Organs  to  aid  in  Pollination. 

—  Besides  the  slow  movements  which  the  stamens  and 
pistil  make  in  such  cases  as  those  of  the  Clerodendron  and 
the  mallow,  already  described,  the  parts  of  the  flower 
often  admit  of  considerable  and  rather  quick  movements 
to  assist  the  insect  visitor  to  become  dusted  or  smeared 
with  pollen. 

In  some  flowers  whose  stamens  perform  rapid  move- 
ments when  an  insect  enters,  it  is  easy  to  see  how  directly 


FIG.  258.  —  Two  Flowers  of  Common  Sage,  one  of  them  visited  by  a  Bee. 

useful  the  motion  of  the  stamens  is  in  securing  cross- 
pollination.  The  stamens  of  the  laurel,  Kalmia,  throw 
little  masses  of  pollen,  with  a  quick  jerk,  against  the 
body  of  the  visiting  insect.  Barberry  stamens  spring  up 
against  the  visitor  and  dust  him  with  pollen.  The  common 
garden  sage  matures  its  anthers  earlier  than  its  stigmas. 
In  Fig.  258,  A,  the  young  flower  is  seen,  visited  by  a  bee, 
and  one  anther  is  shown  pressed  closely  against  the  side 
of  the  bee's  abdomen.  The  stigma,  st,  is  hidden  within 
the  upper  lip  of  the  corolla.  In  B,  an  older  flower,  the 


366 


FOUNDATIONS   OF   BOTANY 


anthers  have  withered  and  the  stigma  is  now  lowered  so 
as  to  brush  against  the  body  of  any  bee  which  may  enter. 

A  little  study  of  Fig.  259 
will  make  clear  the  way 
in  which  the  anthers  are 
hinged,  so  that  a  bee  strik- 


FIG.  259.  —  Flower  and  Stamens  of  Common  Sage. 

A,  p,  stigma  ;  a,  anthers  ;  B,  the  two  stamens  in  ordinary  position  ;  /,  filaments  ; 
m,  connective  (joining  anther-cells)  ;  a',  anther-cells  ;  C,  the  anthers  and 
connectives  bent  into  a  horizontal  position  by  an  insect  pushing  against  a. 


ing  the 
bearing 
will  lie 


empty  or  barren  anther-lobes,  a,  knocks  the  pollen- 
lobes,  a\  into  a  horizontal  position,  so  that  they 
closely  pressed  against  either  side  of  its  abdomen. 

437,  Flowers  with  Sta- 
mens and  Pistils  Each  of  Two 
Lengths.  —  The  flowers  of 
bluets,  partridge-berry,  the 
primroses,  and  a  few  other 
common  plants  secure  cross- 
pollination  by  having  essen- 
tial organs  of  two  forms 
(Fig.  260).  Such  flowers 
are  said  to  be  dimorphous 
(of  two  forms).  In  the 
short-styled  flowers,  II,  the 
anthers  are  borne  at  the  top 
of  the  corolla  tube  and  the 


FIG.  260.  —  Dimorphous  Flowers  of 

the  Primrose. 
i,  a  *>•**"  n'  a  short- 


ECOLOGY   OF  FLOWERS  367 

stigma  stands  about  halfway  up  the  tube.  In  the  long- 
styled  flowers,  I,  the  stigma  is  at  the  top  of  the  tube  and 
the  anthers  are  borne  about  halfway  up.  An  insect  pressing 
its  head  into  the  throat  of  the  corolla  of  II  would  become 
dusted  with  pollen,  which  would  be  brushed  off  on  the 
stigma  of  a  flower  like  I.  On  leaving  a  long-styled  flower 
the  bee's  tongue  would  be  dusted  over  with  pollen,  some 
of  which  would  necessarily  be  rubbed  off  on  the  stigma  of 
the  next  short-styled  flower  that  was  visited.  Cross-polli- 
nation is  insured,  since  all  the  flowers  on  a  plant  are  of 
one  kind,  either  long-styled  or  short-styled,  and  since  the 
pollen  is  of  two  sorts,  each  kind  sterile  on  the  stigma  of 
any  flower  of  similar  form  to  that  from  which  it  came. 

Trimorphous  flowers,  with  long,  medium,  and  short 
styles,  are  found  in  a  species  of  loosestrife.1 

438.  Studies  in  Insect  Pollination.  —  The  student  cannot  gather 
more  than  a  very  imperfect  knowledge  of  the  details  of  cross-polli- 
nation in  flowers  without  actually  watching  some  of  them  as  they 
grow,  and  observing  their  insect  visitors.  If  the  latter  are  caught 
and  dropped  into  a  wide-mouthed  stoppered  bottle  containing  a  bit 
of  cotton  saturated  with  chloroform,  they  will  be  painlessly  killed, 
and  most  of  them  may  be  identified  by  any  one  who  is  familiar  with 
our  common  insects.  The  insects  may  be  observed  and  classified 
in  a  general  way  into  butterflies,  moths,  bees,  flies,  wasps,  and  beetles, 
without  being  captured  or  molested. 

Whether  these  out-of-door  studies  are  made  or  not,  several  flowers 
should  be  carefully  examined  and  described  as  regards  their  arrange- 
ments for  attracting  and  utilizing  insect  visitors  (or  birds).  The 
following  list  includes  a  considerable  number  of  the  most  accessible 
flowers  of  spring  and  early  summer,  about  which  it  is  easy  to  get 
information  from  books. 

1  See  Miss  NewelFs  Reader  in  Botany,  Part  II,  pp.  60-63. 


368  FOUNDATIONS   OF   BOTANY 

LIST   OF   INSECT-POLLINATED   FLOWERS.1 

I 

1.  Flax Linum  usitatissimum Mull. 

2.  Missouri  currant     .     Eibes  aureum Mull. 

3.  Snowberry     .     .     .     Symphoricarpus  racemosus     ....  Mull. 

4.  Lilac Syringa  persica    ....     I     ...  Mull. 

5.  Periwinkle     .     .     .     Vinca  minor Mull. 

6.  Mignonette    .     .     .     Reseda  odorata Mull. 

7.  Pansy Viola  tricolor Miill. 

8.  Dead  nettle    .     .     .     Lamium  album Lubbock. 

9.  Bleeding  heart   .     .     Dicentra  (Diclytra)  spectabilis     .     .     .  Miill. 

10.  Columbine     .     .     .     Aquilegia  vulgaris    .......  Miill. 

11.  Monkshood   .     .     .     Aconitum  Napellus Mull. 


II 

12.  Larkspur  ....  Delphinium  elatum,  D.  consolida     .     .     Miill. 

13.  Herb  Robert .     .     .  Geranium  robertianum  ......     Mull. 

14.  Pink Dianthus  (various  species)       ....     Miill. 

15.  Fireweed  ....     Epilobium  angustifolium Gray. 

16.  Nasturtium    .     .     .  Tropceolum  majus      .     .     .    Newell,  Lubbock. 

17.  Lily-of -the- valley    .     Convallaria  majalis Miill. 

18.  Heal-all     ....  Brunella  (Prunella)  vulgaris  ....     Miill. 

19.  Ground  ivy    .     .     .  Nepeta  Glechoma      ....     Miill.,  Newell. 

20.  Lousewort     .     .     .  Pedicular  is  canadensis .     .     .     Miill.,  Newell. 

21.  Snapdragon  .     .     .     Antirrhinum  majus Miill. 

22.  Iris Iris  versicolor Newell. 

23.  Bellflower      .     .     .  Campanula  rapunculoides      ....     Miill. 

24.  Horse-chestnut  .     .  ^sculus  Hippocastanum  ....      Newell. 

1  The  plants  in  this  list  are  arranged  somewhat  in  the  order  of  the  com- 
plexity of  their  adaptations  for  insect  pollination,  the  simplest  first.  It  would 
be  well  for  each  student  to  take  up  the  study  of  the  arrangements  for  the 
utilization  of  insect  visitors  in  several  of  the  groups  above,  numbered  with 
Roman  numerals.  The  teacher  will  find  explanations  of  the  adaptations  in 
the  works  cited  by  abbreviations  at  the  right.  Miill.  stands  for  Miiller's  Fer- 
tilization of  Flowers;  Lubbock,  for  British  Wild  Flowers,  considered  in 
Relation  to  Insects;  Gray,  for  Gray's  Structural  Botany;  and  Newell,  for 
Miss  Newell's  Outlines  of  Lessons  in  Botany,  Part  II.  Consult  also  Weed's 
Ten  New  England  Blossoms.  »  « 


ECOLOGY   OF  FLOWERS 


369 


III 

25.  Yarrow Achillea  millefolium Mull. 

26.  Oxeye  daisy  .     .     .     Chrysanthemum  Leucanthemum  .     .     .     Miill. 

27.  Dandelion      .     .     .     Taraxacum  officinale     .     .     .    Mull.,  Newell. 

IV 

28.  Barberry  ....     Berberis  vulgaris Lubbock. 

29.  Mountain  laurel      .     Kalmia  latifolia Gray. 


30.  White  clover . 

31.  Ked  clover     . 

32.  Locust. 

33.  Wistaria    .     . 

34.  Vetch   .     .     . 

35.  Pea.     .     .     . 

36.  Bean    .     .     . 

37.  Ground-nut   . 


38.  Partridge-berry  . 

39.  Primrose  .     *    . 

40.  Loosestrife     . 


41.    Milkweed. 


42.    Lady's-slipper    . 


Trifolium  repens Mull. 

Trifolium  pratense Mull. 

Robinia  Pseudacacia Gray. 

Wistaria  sinensis Gray. 

Vicia  cracca Miill. 

Pisum  sativum Miill. 

Phaseolus  vulgaris Gray. 

Apios  tuber osa Gray. 

VI 

Mitchella  repens Gray. 

Primula  grandiflora,  P.  ojficinalis  .  Lubbock. 

Ly thrum  Salicaria Gray. 


VII 

Asclepias  Cornuti     , 

VIII 

Cypripedium  acaule 


.     .    Miill.,  Newell. 


Newell. 


439.  Cleistogamous  Flowers.  —  In  marked  contrast  with 
such  flowers  as  those  discussed  in  the  preceding  sections, 
which  bid  for  insect  visitors  or  expose  their  pollen  to  be 
blown  about  by  the  wind,  are  certain  flowers  which  remain 
closed  even  during  the  pollination  of  the  stigma.  These 
flowers  are  called  cleistogamous  and  of  course  are  not 


370 


FOUNDATIONS   OF  BOTANY 


cross-pollinated.      Usually  they    occur    on   plants    which 
also  bear  flowers  adapted  for  cross-pollination,  and  in  this 


FIG.  261.  — A  Violet,  with  Cleistogamous  Flowers. 

The  objects  which  look  like  flower-buds  are  cleistogamous  flowers  in  various 
stages  of  development.  The  pods  are  the  fruit  of  similar  flowers.  The 
plant  is  represented  as  it  appears  in  late  July  or  August,  after  the  ordi- 
nary flowers  have  disappeared. 


ECOLOGY  OF  FLOWERS 


371 


case  the  closed  flowers  are  much  less  conspicuous  than 
the  others,  yet  they  produce  much  seed.  Every  one 
knows  the  ordinary  flowers  of  the  violet,  but  most  people 


FIG.  262.  —  Protection  of  Pollen  from  Moisture. 

At  the  left  herb  Robert  and  sweet  scabious  in  sunny  weather  ;  at  the  right 
the  same  flowers  during  rain. 

do  not  know  that  violets  very  generally,  after  the  blos- 
soming season  (of  their  showy  flowers)  is  over,  produce 
many  cleistogamous  flowers,  as  shown  in  Fig.  261. 


372  FOUNDATIONS   OF  BOTANY 

440.  Protection  of  Pollen  from  Rain.  —  Pollen  is  very 
generally  protected  from  being  soaked  and  spoiled  by  rain 
or  dew  either  by  the  natural  position  of  the  flower  prevent- 
ing rain  from  entering,  as  in  the  case  with  most  gamo- 
petalous,  nodding  flowers,  or  by  changes  in  the  position 
of  the  flower,  and  by  its  opening  in  sunny  weather  and 
closing  at  night  or  during  rain.  Sometimes  the  flower 
both  changes  its  position  and  closes,  as  is  the  case  with 
the  herb  Robert  and  the  sweet  scabious  (Fig.  262).  The 
adaptations  of  flowers  to  protect  their  pollen  from  becom- 
ing wet  can  best  be  understood  by  actually  examining  the 
same  flower  in  sunshine  and  during  rain. 


PLATE  XI.  —  Aster  and  Golden-Rod 


CHAPTER    XXIX 
HOW    PLANTS    ARE   SCATTERED    AND    PROPAGATED 

441.  Means  of  Propagation  among  Cryptogams.  —  Some 
of  the  highest  cryptogams,  as  the  ferns,  spread  freely  by 
means  of  their  creeping  rootstocks,  and  the  gardener  who 
wishes  quickly  to  get  large,  strong  ferns  often  finds  it  the 
easiest  plan  to  cut  to  pieces  and  reset  the  rootstocks  of  a 
well-established  plant.     Some  ferns  also  grow  readily  from 
bulblets  produced   on  the  fronds.      In  the  walking  fern 
the  tip  of  the  frond  roots  and  begins  a  new  plant.     Most 
flowerless  plants,  however,   are  reproduced    either   by  a 
process  of  fission,  as  in  Pleurococcus  (Sect.  278),  Diatoms 
(Sect.  271),  Bacteria  (Sect.  266),  and  many  other  groups, 
or   by  some    kind    of   spore   (Sect.   259).     The  spore    is 
usually  so  small  an  object  that  it  is  carried  with  the  great- 
est ease  by  currents  of  water  or  of  air,  as  the  case  may 
be,  so  that  it  is  no  sooner  liberated  than  it  is  swept  away, 
often  to  a  very  distant  locality,  where  it  can  grow  and  not 
be  interfered  with  by  too  many  neighbors  of  its  own  kind. 
Thus  spores  of  any  of  the  marine  algse  are  certainly  carried 
thousands  of  miles  by  ocean  currents,  and  spores  of  tree 
ferns  may  be  blown  great  distances  from  one  oceanic  island 
to  another,  or  the  spore  contents  of  a  puff-ball  might  travel 
on  the  wind  half  the  breadth  of  a  continent. 

442.  Dispersal  of  Seed-Plants  by  Roots  and  Rootstocks.— 
The  student  has  learned  (in   Chapters  IV  and  V)   that 
roots  and  underground  stems  of  many  kinds  may  serve  to 

373 


374  FOUNDATIONS  OF  BOTANY 

reproduce  the  plant.  Either  roots  or  rootstocks  may  travel 
considerable  distances  horizontally  in  the  course  of  their 
growth  and  then  shoot  up  and  produce  a  new  plant,  which 
later  becomes  independent  of  the  parent.  The  sedges  (Fig. 
43)  are  excellent  illustrations  of  this  process,  and  trees 


like  the  common 
locust  and  the 
silver-leaf  poplar 
become  great  nui- 
sances in  the  neigh- 
borhood of  lawns 

FIG.  263.  —  Plant    of   a  Black 

Raspberry,  showing  One  and    gardens    by 


in  many  places.  When  growing 
wild,  such  trees  as  these  depend  largely  upon  spreading 
by  the  roots  to  keep  up  their  numbers.1 

443,  Dispersal  of  Seed-Plants  by  Branches.  —  There  is  a 
shrub  of  the  Honeysuckle  Family,2  common  in  the  northern 
woods,  which  is  quite  generally  known  as  hobble-bush,  or 
witch-hobble,  and  sometimes  as  trip-toe.  This  is  because 
the  branches  take  root  at  the  end  and  so  form  loops  which 
catch  the  foot  of  the  passer-by.  The  same  habit  of  growth 
is  found  in  the  raspberry-bush  (Fig.  263),  in  one  species  of 
strawberry-bush  (Euonymus),  and  some  other  shrubs.  Many 
herbs  like  the  strawberry-plant  and  the  cinquefoil  send 

1  See  Beal's  Seed  Dispersal,  Chapters  II  and  in. 

2  Viburnum  lantanoides. 


HOW   PLANTS   ARE    SCATTERED 


375 


out  long,  leafless  runners  which  root  at  intervals  and  so 
propagate  the  plant,  carrying  the  younger  individuals  off 
to  a  considerable  distance  from  the  parent  plant. 

Living  branches  may  drop  freely  from  the  tree  and  then 
take  root  and  grow,  after  having  been  blown  or  been  car- 
ried by  a  brook  or  river  to  a  favorable  spot,  perhaps  hun- 
dreds of  yards  away.  The  so-called  snap-willows  lose 
many  live  twigs  under  conditions  suit- 
able for  starting  new  trees. 

A  slightly  different  mode  of  dis- 
persal from  that  of 
the  raspberry  is  one 
in  which  buds  sepa- 
rate from  the  plant 
and  serve  to  propa- 
gate it.  In  the  blad- 
derwort  (Fig.  264), 
at  the  close  of  the 
growing  season,  the 
terminal  buds  are  released  by  the  decay  of  the  stem  and 
sink  to  the  bottom  of  the  water  in  which  the  plants  live, 
there  to  remain  dormant  until  spring.  Then  each  bud 
starts  into  life  and  gives  rise  to  a  new  individual. 

444.  Dispersal  of  Seed-Plants  by  Bulblets.  —  Almost 
every  farmer's  boy  knows  what  "onion-sets"  are.  These 
are  little  bulbs,  produced  at  the  top  of  a  naked  flower- 
stalk  or  scape  by  some  kinds  of  onions  which  do  not 
usually  flower  or  bear  seed.  Tiger-lilies  produce  some- 
what similar  bulblets  in  the  axils  of  the  leaves,  and  there 
is  a  large  number  of  species,  scattered  among  numerous 
families  of  plants,  all  characterized  by  the  habit  of  producing 


FIG.  264.  — A  Free  Branch  and  Two  Buds  of 
Bladderwort. 


376 


FOUNDATIONS   OF   BOTANY 


bulblets.  When  mature  the  bulblets  fall  off  readily,  and  if 
they  find  lodgment  on  unoccupied  soil,  they  grow  readily 
into  new  plants.  Sometimes  they  are  carried  moderate 
distances  by  wind  or  water,  and  if  the  ground  slopes,  they 
may  easily  roll  far  enough  to  get  started  in  new  places. 


FIG.  265.  —  Fruit  of  Smoke-Tree  (Rhus  Cotinus). 

Only  one  pedicel  bears  a  fruit,  all  the  others  are  sterile,  branched ,  and  covered 
with  plumy  hairs. 

445.  Dispersal  of  Seeds.  —  Seeds  are  not  infrequently 
scattered  by  apparatus  by  which  the  plant  throws  them 
about.  More  commonly,  however,  they  depend  upon 
other  agencies,  such  as  wind,  water,  or  animals,  to  carry 
them.  Sometimes  the  transportation  of  seeds  is  due  to 


HOW   PLANTS   ARE   SCATTERED 


377 


the  structure  of  the  seeds  themselves,  sometimes  to  that 
of  the  fruit  in  which  they  are  enclosed  ;  the  essential 
point  is  to  have  transportation  to  a  long  distance  made 
as  certain  as  possible,  to  avoid  overcrowding. 

446.  Explosive   Fruits.  —  Some  dry  fruits  burst   open 
when  ripe  in  such  a  way  as  to  throw  their  seeds  violently 
about.      Interesting 

studies  may  be  made, 
in  the  proper  season, 
of  the  fruits  of  the 
common  blue  violet, 
the  pansy,  the  wild 
balsam,  the  garden 
balsam,  the  crane's- 
bill,  the  herb  Robert, 
the  witch-hazel,  the 
Jersey  tea,  and  some 
other  common  plants. 

The     Capsule     Of     the      FIG- 266. -Fruits  of  Linden,  with  a  Bract  joined 
r  <  to  the  Peduncle  and  forming  a  Wing. 

tropical  American 

sand-box  tree  bursts  open  when  thoroughly  dry  with  a  noise 

like  that  of  a  pistol  shot. 

447.  Winged  or  Tufted  Fruits  and  Seeds.  —  The  fruits 
of  the  ash,  box-elder,  elm,  maple  (Fig.  169),  and  many 
other  trees,  are  provided  with  an  expanded  membranous 
wing.    Some  seeds,  as  those  of  the  catalpa  and  the  trumpet- 
creeper,    are   similarly    appendaged.     The    fruits    of   the 
dandelion,  the  thistle  (Fig.  267),  the  fleabane,  and  many 
other  plants  of  the  group  to  which  these  belong,  and  the 
seeds  of  the  willow,  the  milkweed  (Fig.  267),  the  willow- 
herb,  and  other  plants,  bear  a  tuft  of  hairs. 


378 


FOUNDATIONS   OF   BOTANY 


The  student  should  be  able,  from  his  own  observations  on 
the  falling  fruits  of  some  of  the  trees  and  other  plants  above 
mentioned,  to  answer  such  questions  as  the  following  : 

What  is  the  use  of 
the  wing-like  append- 
ages? of  the  tufts  of 
hairs? 

Which  set  of  con- 
trivances seems  to  be 
the  more  successful  of 
the  two  in  securing 
this  object? 

What  particular 
plant  of  the  ones  avail- 
able for  study  seems 
to  have  attained  this 
object  most  perfectly  ? 

What  is  one  reason 
why  many  plants  with 
tufted  fruits,  such  as 
the  thistle  and  the  dan- 
delion, are  extremely 
troublesome  weeds? 

A  few  simple  experi- 
ments, easily  devised 
by  the  student,  may 
help  him  to  find  an- 
swers to  the  questions 
above  given.1 


FIG.  267.  —  "Winged  Fruits  of  Thistle  ;  Winged  Seeds 
of  Milkweed. 


448.  Tumbleweeds.  —  Late  in  the  autumn,  fences,  par- 
ticularly on  prairie  farms  that  are  not  carefully  tilled,  often 
serve  as  lodging-places  for  immense  numbers  of  certain 
dried-up  plants  known  as  tumbleweeds.  These  blow 
about  over  the  level  surface  until  the  first  snow  falls  and 


1  See  Kerner  and  Oliver,  Vol.  II,  pp.  833-875 ;  also  Seal's  Seed  Dispersal 


HOW   PLANTS  ARE   SCATTERED 


379 


even  after  that  (Fig.  269),  often  traveling  for  many  miles 
before  they  come  to  a  stop,  and  rattling  out  seeds  as  they 
go.  Some  of  the  commonest  tumbleweeds  are  the  Russian 
thistle  (Fig.  268),  the  pigweed  (Amarantus  albus.  Fig.  269), 
the  tickle-grass  (Fig.  270),  and  a  familiar  pepper-grass 
(Lepidium).  In  order  to  make  a  successful  tumbleweed,  a 
plant  must  be  pretty  nearly  globular  in  form  when  fully 
grown  and  dried,  must  be  tough  and  light,  must  break  off 
near  the  ground,  and  drop  its  seeds  only  a  few  at  a  time 
as  it  travels.  A  single  plant 
of  Russian  thistle  is  some- 
times as  much  as  three  feet 
high  and  six  feet  in  diameter 
and  carries  not  less  than  two 
hundred  thousand  seeds. 

449.  Many -Seeded  Pods 
with  Small  Openings. — 
There  are  many  fruits  which 
act  somewhat  like  pepper- 
boxes. The  capsule  of  the 
poppy  is  a  good  instance  of 
this  kind,  and  the  fruit  of 
lily,  monkshood  (Fig.  168), 
columbine,  larkspur,  and 
jimson  weed  (Fig.  271)  acts 
in  much  the  same  way. 
Clamping  the  dry  peduncle 
of  any  one  of  these  ripe 

£      .,  i     1  T    •,  PIG.  268.— Russian  Thistle. 

fruits,  so  as  to  hold  it  up- 
right above  the  table-top,  and  then  swinging  it  back  and 
forth,  will  readily  show  its  efficiency  in  seed  dispersal. 


380 


FOUNDATIONS   OF   BOTANY 


450,  Study  of  Transportation  by  Water.  —  Nothing  less 
than  a  long  series  of  observations  by  the  pond-margin  and 
the  brookside  will  suffice  to  show  how  general  and  impor- 


FIG.  269.  —  Tumbleweeds 1  lodged  against  a  Wire  Fence  in  Winter. 

tant  is  the  work  done  by  water  in  carrying  the  seeds  of 
aquatics.  An  experiment  will,  however,  throw  some  light 
on  the  subject. 

EXPERIMENT   XL 

Adaptation  for  Transportation  by  Water.  —  Collect  fruits  of  as 
many  aquatic,  semi-aquatic,  or  riverside  and  brookside  species  of 
plants  as  possible,  place  them  on  shallow  pans  of  water  and  notice 
what  proportion  of  all  the  kinds  studied  will  float.  Leave  them 
twenty-four  hours  or  more  and  see  whether  all  the  kinds  that  floated 
at  first  are  still  afloat.  Some  desirable  fruits  for  this  experiment 

1  Amarantus  albus. 


HOW   PLANTS   ARE    SCATTERED 


381 


1 


are  :  aquatic  grasses,  rushes  and  sedges,  polygon  urns,  water-dock, 
bur-reed,  arrowhead,  water-plantain,  pickerel-weed,  alder,  button- 
bush,  water-parsnip  (Sium),  water-hemlock  (Cicuta),  water  penny- 
wort (Hydrocotyle). 

451.  Distances  traversed  by  Floating  Seeds.  —  Ocean 
currents  furnish  transportation  for  the  longest  journeys 
that  are  made  by  floating 

seeds.  It  is  a  well-known 
fact  that  cocoa-palms  are 
among  the  first  plants  to 
'spring  up  on  newly  formed 
coral  islands.  The  nuts 
from  which  these  palms 
grew  may  readily  have 
floated  a  thousand  miles 
or  more  without  injury. 
On  examining  a  cocoanut 
with  the  fibrous  husk  at- 
tached, just  as  it  fell  from 
the  tree,  it  is  easy  to  see  - 
how  well  this  fruit  is 
adapted  for  transportation 
by  water.  There  are  al- 
together about  a  hundred 
drifting  fruits  known,  one 
(the  Maldive  nut)  reach- 
ing a  Weight  of  twenty  to  FIG.  270.  —  Panicle  of  Tickle-Grass,  a 
,  r>  T  Common  Tumbleweed. 

twenty-five  pounds. 

452,  Burs.  —  A  large  class  of  fruits  is  characterized  by 
the  presence  of  hooks  on  the  outer  surface.     These  are 
sometimes    outgrowths  from  the   ovary,  sometimes  from 


382  FOUNDATIONS   OF   BOTANY 

the  calyx,  sometimes  from  an  involucre.  Their  office  is 
to  attach  the  fruit  to  the  hair  or  fur  of  passing  animals. 
Often,  as  in  sticktights  (Fig.  272),  the  hooks  are  compara- 
tively weak,  but  in  other  cases,  as  in  the  cocklebur  (Fig. 
272),  and  still  more  in  the  Martynia,  the  fruit  of  which 
in  the  green  condition  is  much  used  for  pickles,  the 
hooks  are  exceedingly  strong.  Cockleburs  can  hardly  be 
removed  from  the  tails  of  horses  and  cattle,  into  which 


i  ii  in 

FIG.  271.  —  Three  Fruits  adapted  for  Dispersal  by  the  Shaking  Action  of  the  Wind. 
I,  celandine  ;  II,  pea ;  III,  jimson  weed  (Datura). 

they  have  become    matted,  without  cutting  out  all  the 
hairs  to  which  they  are  fastened. 

A  curious  case  of  distribution  of  this  kind  occurred 
in  the  island  of  Ternate,  in  the  Malay  Archipelago.  A 
buffalo  with  his  hair  stuck  full  of  the  needle-like  fruits  of 
a  grass1  was  sent  as  a  present  to  the  so-called  King  of 
Ternate.  Scattered  from  the  hair  of  this  single  animal, 
the  grass  soon  spread  over  the  whole  island. 

1  Andropogon  acicularis. 


HOW  PLANTS   AKE   SCATTERED 


383 


Why  do  bur-bearing  plants  often  carry  their  fruit  until 
late  winter  or  early  spring? 

What  reason  can  be  given  for  the  fact  that  the  burdock, 
the  cocklebur,  the  beggar's-ticks,  the  hound's-tongue,  and 
many  other  common  burs,  are  among  the  most  persistent 
of  weeds  ? 

453,  Uses  of  Stone  Fruits  and  of  Fleshy  Fruits  to  the 
Plant.  —  Besides  the  dry  fruits,  of  which  some  of  the 
principal  kinds  have  been  mentioned,  there  are  many  kinds 


FIG.  272. —  Burs. 

A,  sticktights  ;  B,  sticktights,  two  segments,  magnified ; 
C,  burdock  ;  D,  cockleburs. 

of  stone  fruits  and  other  fleshy  fruits  (Sects.  242-247). 
Of  these  the  great  majority  are  eatable  by  man  or  some  of 
the  lower  animals,  and  oftentimes  the  amount  of  sugar 
and  other  food  material  which  they  contain  is  very  con- 
siderable. It  is  a  well-recognized  principle  of  botany,  and 


384 


FOUNDATIONS    OF  BOTANY 


of  zoology  as  well,  that  plants  and  animals  do  not  make 
unrewarded  outlays  for  the  benefit  of  other  species.  Evi- 
dently the  pulp  of  fruits  is  not  to  be  consumed  or  used 


FIG.  273.  —  Barbs  and  Hooks  of  Burs. 

I,  barbed  points  from  fruit  of  beggar 's-ticks,  magnified  eleven  times ; 
•  II,  hook  of  cocklebur,  magnified  eleven  times ;  III,  beggar's-ticks 
fruit,  natural  size ;  IV,  cocklebur  hook,  natural  size. 

as  food  by  the  plant  itself  or  (in  general)  by  its  seeds.  It 
is  worth  while,  therefore,  for  the  student  to  ask  himself 
some  such  questions  as  these : 1 

(1)  Why  is  the  pulp  of  so  many  fruits  eatable  ? 

(2)  Why  are  the  seeds  of  many  pulpy  fruits  bitter  or 
otherwise  unpleasantly  flavored,  as  in  the  orange  ? 

(3)  Why  are  the  seeds  or  the  layers  surrounding  the 

1  See  Kerner  and  Oliver's  Natural  History  of  Plants,  Vol.  II,  pp.  442-450. 


HOW    PLANTS    ARE    SCATTERED 


385 


seeds   of  many  pulpy  fruits  too  hard  to  be  chewed,  or 
digested,  as  in  the  date  and  the  peach? 

(4)  Why  are  the  seeds  of  some  pulpy  fruits  too  small 
to  be  easily  chewed,  and  also  indigestible,  as  in  the  fig 
and  the  currant? 

(5)  Account  for  the  not  infrequent  presence  of  currant 
bushes  or  asparagus  plants  in  such  localities  as  the  forks 
of  large  trees,  sometimes  at  a  height  of  twenty,  thirty,  or 
more  feet  above  the  ground  (Fig.  274). 

Careful  observation  of  the  neighborhood  of  peach,  plum, 
cherry,  or  apple  trees  at  the  season  when  the  fruit  is  ripe 
and  again  during  the  following  spring,  and  an  examina- 
tion into  the  distribution  of  wild 
apple  or  pear  trees  in  pastures 
where  they  occur,  will  help  the 
student  who  can  make  such  ob- 
servations to  answer  the  preced- 
ing questions.     So,  too,  would 
an  examination  of  the  habits  of 
fruit-eating  quadrupeds  and  of 
the  crop   and  gizzard  of  fruit- 
eating  birds  during  the  season 
when  the  fruits  upon  which  they 
feed  are  ripe. 

454.  Seed-Carrying  purposely 
done  by  Animals.  —  In  the  cases 
referred  to  in  the  preceding  sec- 
tions, animals  have  been  seen 
to  act  as  unconscious  or  even  unwilling  seed-carriers. 
Sometimes,  however,  they  carry  off  seeds  with  the  plan 
of  storing  them  for  food.  Ants  drag  away  with  them  to 


FIG.  274.  —  Red  Rasp- 
berry Bush,  in  Fork 
of  a  Maple. 


386 


FOUNDATIONS   OF   BOTANY 


their  nests  certain  seeds  which  have   fleshy  growths    on 
their  outer  surfaces.      Afterwards  they  eat  these  fleshy 


FIG.  275.  —  Red  Cedar  Trees  planted  by  Birds  roosting  on  Fences. 

parts  at  their  leisure,  leaving  the  seed  perfectly  fit  to 
grow,  as  it  often  does.1 

Squirrels   and  bluejays   are  known  to  carry  nuts  and 
acorns    about    and   bury    them    for    future    use.       These 


FIG.  276.  —  Seed  of  Bloodroot  with  Caruncle  or  Crest,  which  serves  as  a  Handle 
for  Ants  to  hold  on  to.    Ant  ready  to  take  the  seed. 

deposits  are  often  forgotten  and  so  get  a  chance  to  grow, 
and  in  this  way  a  good  deal  of  tree-planting  is  done. 

1  See  Beal's  Seed  Dispersal,  pp.  (39,  70. 


CHAPTER    XXX 

THE    STRUGGLE    FOR    EXISTENCE   AND    THE    SURVIVAL 
OF    THE    FITTEST1 

455.  Weeds.  —  Any  flowering  plant  which  is  trouble- 
some to  the  farmer  or  gardener  is  commonly  known  as  a 
weed.  Though  such  plants  are  so  annoying  from  their 
tendency  to  crowd  out  others  useful  to  man,  they  are  of 
extreme  interest  to  the  botanist  on  account  of  this  very 
hardiness.  The  principal  characteristics  of  the  most  suc- 
cessful weeds  are  their  ability  to  live  in  a  variety  of  soils 
and  exposures,  their  rapid  growth,  resistance  to  frost, 
drought,  and  dust,  their  unfitness  for  the  food  of  most  of 
the  larger  animals,  in  many  cases  their  capacity  to  accom- 
plish self-pollination,  in  default  of  cross-pollination,  and 
their  ability  to  produce  many  seeds  and  to  secure  their 
wide  dispersal.  Not  every  weed  combines  all  of  these 
characteristics.  For  instance,  the  velvet-leaf  or  butter- 
print,2  common  in  cornfields,  is  very  easily  destroyed  by 
frost ;  the  pigweed  and  purslane  are  greedily  eaten  by  pigs, 
and  the  ragweed  by  some  horses.  The  horse-radish  does 
not  usually  produce  any  seeds. 

It  is  a  curious  fact  that  many  plants  which  have  finally 
proved  to  be  noxious  weeds  have  been  purposely  intro- 
duced into  the  country.  The  fuller's  teasel,  melilot, 
horse-radish,  wild  carrot,  wild  parsnip,  tansy,  oxeye  daisy, 

1  See  Darwin's  Origin  of  Species,  Chapters  III  and  IV. 

2  Abutilon  Avicennse. 

387 


388  FOUNDATIONS   OF  BOTANY 

and  field-garlic  are  only  a  few  of  the  many  examples  of 
very  troublesome  weeds  which  were  at  first  planted  for 
use  or  for  ornament. 

456.  Study  of  Weeds.  —  Select  two  or  more  out  of  the 
following  list  of  weeds  and  report  on  the  qualities  which 
make  them  troublesome  from  the  farmer's  point  of  view 
(successful  from  their  own).1 

LIST   OF   WEEDS2 

1.  Barn-grass,*  Panicum  Crus-galli. 

2.  Beggar's  lice,*  Cynoglossum  officinale. 

3.  Beggar's-ticks,  Bidens  frondosa. 

4.  Black  mustard,*  Brassica  nigra. 

5.  Blue  thistle,*  Echium  vulgare. 

6.  Buffalo  bur,  Solarium  rostratum. 

7.  Burdock,*  Arctium  Lappa. 

8.  Buttercup,*  Ranunculus  bulbosus. 

9.  Butterweed,*  Erigeron  canadensis. 

10.  Carpet  weed,  Mollugo  verticillata. 

11.  Charlock,*  Brassica  Sinapistrum. 

12.  Chess  or  cheat,*  Bromus  secalinus. 

13.  Chickweed,  Stellaria  media.  » 

14.  Chicory,*  Cichorium  Intybus. 

15.  Clover  dodder,*  Cuscuta  Trifolii. 

16.  Cocklebur,*  XantJiium  spinosum. 

17.  Corn  cockle,*  Agrostemma  Giihago. 

1  This  study  will  be  of  little  value  in  city  schools,  since  the  plants  should 
be  examined  as  they  grow.     Specimens  of  the  mature  weed  and  of  its  fruits 
and  seeds  may  be  preserved  by  the  teacher  from  one  season  to  another  for 
class  use.     Whole  specimens  of  small  plants,  such  as  purslane,  may  be  put 
into  preservative  fluid  (see  Handbook).     Ordinary  weeds,  such  as  ragweed, 
pigweed,  etc.,   may  be  pressed   and  kept  as  roughly  prepared  herbarium 
specimens,  while  such  very  large  plants  as  jimson  weed,  dock,  etc.,  may  be 
hung  up  by  the  roots  and  thus  dried. 

2  Names  marked  in  the  list  thus  *  are  those  of  plants  introduced  from 
other  countries,  mostly  from  Europe. 


THE   STRUGGLE   FOR   EXISTENCE  389 

18.  Cow  herb,*  Saponaria  Vaccaria. 

19.  Daisy,  oxeye,*  Chrysanthemum  Leucanthemum. 

20.  Dandelion,*  Taraxacum  ojficinale. 

21.  Dock,  Rumex  crispus. 

22.  Dog  fennel,*  Anthemis  cotula. 

23.  Fox-tail  grass,*  Setaria  glauca. 
24.-  Horse-nettle,  Solarium  carolinense. 

25.  Jamestown  weed  or  Jimson  weed,*   Datura  Stramonium 

or  D.  Tatula. 

26.  Johnson  grass,  Andropogon  halepensis. 

27.  Mallow,*  Malva  rotundifolia. 

28.  Milkweed,  Asclepias  Cornuti. 

29.  Nettle,  Urtica  gracilis. 

30.  Pigweed,*  Amarantus  retrojlexus. 

31.  Pigweed,*  Chenopodium  album. 

32.  Plantain,*  Plantago  major. 

33.  Pokeberry,  Phytolacca  decandra. 

34.  Purslane,  Portulaca  oleracea. 

35.  Quick-grass,*  Witchgrass,  Agropyrum  repens. 

36.  Ragweed,  Ambrosia  artemisicefolia. 

37.  Rib  grass,*  Plantago  lanceolata. 

38.  Sand  bur,  Cenchrus  tribuloides. 

39.  Shepherd's  purse,*  Capsella  Bursa-pastoris. 

40.  Smartweed,  Polygonum  Hydropiper. 

41.  Sorrel,*  Rumex  Acetosella. 

42.  Spanish  needles,  Bidens  bipinnata. 

43.  Sticktights,  Desmodium  canadense. 

44.  Thistle,*  Cirsium  lanceolatum,  C.  arvense. 

45.  Yarrow,  Achillea  Millefolium. 

457.  Origin  of  Weeds.1  —  By  far  the  larger  proportion 
of  our  weeds  are  not  native  to  this  country.  Some  have 
been  brought  from  South  America  and  from  Asia,  but 
most  of  the  introduced  kinds  come  from  Europe.  The 
importation  of  various  kinds  of  grain  and  of  garden-seeds, 

1  See  the  article  "  Pertinacity  and  Predominance  of  Weeds,"  in  Scientific 
Papers  of  Asa  Gray,  selected  by  C.  S.  Sargent,  Vol.  II,  pp.  234-242. 


390  FOUNDATIONS   OF   BOTANY 

mixed  with  seeds  of  European  weeds,  will  account  for  the 
presence  of  many  of  the  latter  among  us.  Others  have 
been  brought  over  in  the  ballast  of  vessels.  Once  landed, 
European  weeds  have  succeeded  in  establishing  themselves 
in  so  many  cases,  because  they  were  superior  in  vitality 
and  in  their  power  of  reproduction  to  our  native  plants. 
This  may  not  improbably  be  due  to  the  fact  that  the  Euro- 
pean and  western  Asiatic  vegetation,  much  of  it  consisting 
from  very  early  times  of  plants  growing  in  comparatively 
treeless  plains,  has  for  ages  been  habituated  to  nourish  in 
cultivated  ground  and  to  contend  with  the  crops  which 
are  tilled  there. 

458.  Plant  Life  maintained  under  Difficulties.  —  Plants 
usually  have  to  encounter  many  obstacles  even  to  their 
bare  existence.  For  every  plant  which  succeeds  in  reach- 
ing maturity  and  producing  a  crop  of  spores  or  of  seeds 
there  are  hundreds  or  thousands  of  failures,  as  it  is  easy 
to  show  by  calculation.  The  morning-glory  (Ipomoea  pur- 
pur  ed)  is  only  a  moderately  prolific  plant,  producing,  in 
an  ordinary  soil,  somewhat  more  than  three  thousand 
seeds.1  If  all  these  seeds  were  planted  and  grew,  there 
would  be  three  thousand  plants  the  second  summer,  sprung 
from  the  single  parent  plant.  Suppose  each  of  these 
plants  to  bear  as  the  parent  did,  and  so  on.  Then  there 
would  be  : 

9,000,000  plants  the  third  year. 
27,000,000,000  plants  the  fourth  year. 
81,000,000,000,000  plants  the  fifth  year. 
243,000,000,000,000,000  plants  the  sixth  year. 
729,000,000,000,000,000,000  plants  the  seventh  year. 

1  Rather  more  than  three  thousand  two  hundred  by  actual  count  and 
estimation. 


THE   STRUGGLE   FOR   EXISTENCE  391 

It  is  not  difficult  to  see  that  the  offspring  of  a  single 
morning-glory  plant  would,  at  this  rate,  soon  actually 
cover  the  entire  surface  of  the  earth.  The  fact  that 
morning-glories  do  not  occupy  any  larger  amount  of  ter- 
ritory than  they  do  must  therefore  depend  upon  the  fact 
that  the  immense  majority  of  their  seeds  are  not  allowed 
to  grow  into  mature  plants. 

There  are  many  plants  which  would  yield  far  more  sur- 
prising results  in  a  calculation  similar  to  that  just  given 
than  are  afforded  by  the  morning-glory.  For  instance,  a 
foxglove  capsule  contains  on  an  average  nearly  1800 
seeds.  A  small  foxglove  plant  bears  from  140  to  200  cap- 
sules and  a  large  one  from  530  to  700.  Therefore  a  single 
plant  may  produce  over  1,250,000  seeds.  A  single  orchid 
plant1  has  been  shown  to  produce  over  10,000,000  seeds. 

459.  Importance  of  Dispersal  of  Seeds.  —  It  is  clear  that 
any  means  of  securing  the  wide  distribution  of  seeds  is  of 
vital  importance  in  continuing  and  increasing  the  numbers 
of  any  kind  of  plant,  since  in  this  way  destruction  by  over- 
crowding and  starvation  will  be  lessened. 

A  few  of  the  means  of  transportation  of  seeds  have  been 
described  in  Sects.  445-454,,  but  the  cases  are  so  numerous 
and  varied  that  a  special  treatise  might  well  be  devoted  to 
this  subject  alone. 

460.  Destruction  of  Plants  by  Unfavorable  Climates.  — 
Land-plants,  throughout  the  greater  part  of  the  earth's 
surface,  are  killed  in  enormous  numbers  by  excessive  heat 
and  drought,  by  floods,  or  by  frost.     After  a  very  dry 
spring  or  summer  the  scantiness  of  the  crops,  before  the 
era  of  railroads  which  nowadays  enable  food  to  be  brought 

1  Maxillaria,  see  Darwin's  Fertilization  of  Orchids,  Chapter  IX. 


392  FOUNDATIONS   OF  BOTANY 

in  rapidly  from  other  regions,  often  produced  actual  fam- 
ine. Wild  plants  are  not  observed  so  carefully  as  culti- 
vated ones  are,  but  almost  every  one  has  noticed  the 
patches  of  grass,  apparently  dead,  in  pastures  and  the 
withered  herbaceous  plants  everywhere  through  the  fields 
and  woods  after  a  long  drought. 

Floods  destroy  the  plants  over  large  areas,  by  drowning 
them,  by  sweeping  them  bodily  away,  or  by  covering  them 
with  sand  and  gravel. 

Frosts  kill  many  annual  plants  before  they  have  ripened 
their  seeds,  and  severe  and  changeable  winters  sometimes 
kill  perennial  plants. 

461.  Destruction  by  Other   Plants Overcrowding  is 

one  of  the  commonest  ways  in  which  plants  get  rid  of 
their  weaker  neighbors.     If  the  market-gardener  sows  his 
lettuce  or  his  beets  too  thickly,  few  perfect  plants  will  be 
produced,  and  the  same  kind  of  effect  is  brought  about  in 
nature  on  an  immense  scale.     Sometimes  plants  are  over- 
shadowed and  stunted  or  killed  by  the  growth  all  about 
them  of  others  of  the  same  kind ;  sometimes  it  is  plants 
of  other  kinds  that  crowd  less  hardy  ones  out  of  existence. 

Whole  tribes  of  parasitic  plants,  some  comparatively 
large,  like  the  dodder  and  the  mistletoe,  others  micro- 
scopic, like  blights  and  mildews,  prey  during  their  whole 
lives  upon  other  plants. 

462,  Adaptations   to   meet  Adverse   Conditions.  —  Since 
there  are  so  many  kinds  of  difficulties  to  be  met  before  the 
seed  can  grow  into  a  mature  plant  and  produce  seed  in  its 
turn,  and  since  the  earth's  surface   offers  such  extreme 
variations  as  regards  heat,  sunlight,  rainfall,  and  quality 
of   soil,  it  is  evident  that  there   is   a  great  opportunity 


THE    STRUGGLE   FOR   EXISTENCE  393 

offered  for  competition  among  plants.  Of  several  plants 
of  the  same  kind,  growing  side  by  side,  where  there  is 
room  for  but  one  full-grown  one,  all  may  be  stunted,  or 
one  may  develop  more  rapidly  than  the  others,  starve  them 
out,  and  shade  them  to  death.  Of  two  plants  of  different 
kinds  the  hardier  will  crowd  out  the  less  hardy,  as  ragweed, 
pigweed,  and  purslane  do  with  ordinary  garden  crops. 
Weeds  like  these  are  rapid  growers,  stand  drought  or 
shade  well,  will  bear  to  be  trampled  on,  and,  in  general, 
show  remarkable  toughness  of  organization. 

Plants  which  can  live  under  conditions  that  would  be 
fatal  to  most  others  will  find  much  less  competition  than 
the  rank  and  file  of  plants  are  forced  to  encounter.  Lichens, 
growing  on  barren  rocks,  are  thus  situated,  and  so  are  the 
fresh-water  plants,  somewhat  like  pond-scum  in  their  struc- 
ture, which  are  found  growing  in  hot  springs  at  tempera- 
tures of  140°,  or  in  some  cases  nearly  up  to  200°. 

463,  Examples  of  Rapid  Increase.  —  Nothing  but  the 
opposition  which  plants  encounter  from  overcrowding  or 
from  the  attacks  of  their  enemies  prevents  any  hardy  kind 
of  plant  from  covering  all  suitable  portions  of  a  whole 
continent,  to  the  exclusion  of  most  other  vegetable  life. 
New  Zealand  and  the  pampas  of  La  Plata  and  Paraguay, 
in  South  America,  have,  during  the  present  century,  fur- 
nished wonderful  examples  of  the  spread  of  European 
species  of  plants  over  hundreds  of  thousands  of  square 
miles  of  territory.  The  newcomers  were  more  vigorous, 
or  in  some  way  better  adapted  to  get  on  in  the  world 
than  the  native  plants  which  they  encountered,  and  so 
managed  to  crowd  multitudes  of  the  latter  out  of 
existence. 


394  FOUNDATIONS    OF   BOTANY 

In  our  own  country  a  noteworthy  case  of  the  kind  has 
occurred  so  very  recently  that  it  is  of  especial  interest 
to  American  botanists.  The  so-called  Russian  thistle 
(Fig.  268),  which  is  merely  a  variety  of  the  saltwort,  so 
common  along  the  Atlantic  coast,  was  first  introduced  into 
South  Dakota  in  flaxseed  brought  from  Russia  and  planted 
in  1873  or  1874.  In  twenty  years  from  that  time  the  plant 
had  become  one  of  the  most  formidable  weeds  known,  over 
an  area  of  about  twenty-five  thousand  square  miles. 

464.  Importance  of  Adaptiveness  in  Plants.  —  It  may  be 
inferred  from  the  preceding  sections  that  a  premium  is  set 
on  all  changes  in  structure  or  habits  which  may  enable 
plants  to  resist  their  living  enemies  or  to  live  amid  partially 
adverse  surroundings  of  soil  or  climate.     It  would  take  a 
volume  to  state,  even  in  a  very  simple  way,  the  conclusions 
which  naturalists  have  drawn  from  this  fact  of  a  savage 
competition  going  on  among  living  things,  and  it  will  be 
enough  to  say  here  that  the  existing  kinds  of  plants  to  a 
great  degree  owe  their  structure  and  habits  to  the  operation 
of  the  struggle  for  existence,  this  term  including  the  effort  to 
respond  to  changes  in  the  conditions  by  which  they  are  sur- 
rounded.    How  the  struggle  for  existence  has  brought 
about  such  far-reaching  results  will  be  briefly  indicated  in 
the  next  section. 

465.  Survival  of   the   Fittest.  —  When  frost,  drought, 
blights,  or  other  agencies  kill  most  of  the  plants  in  any 
portion  of  the  country,  it  is  often  the  case  that  many  of 
the  plants  which  escape  do  so  because  they  can  stand  more 
hardship  than  the  ones  which  die.     In  this  way  delicate 
individuals  are  weeded  out  and  those  which    are    more 
robust  survive.     But  other  qualities  besides  mere  toughness 


THE   STRUGGLE   FOR   EXISTENCE  395 

often  decide  which  plant  or  plants  of  any  particular 
kind  shall  live  and  which  ones  shall  die  out.  In  every 
grove  of  oaks  there  are  some  with  sweeter  and  others  with 
more  bitter  acorns.  One  shellbark  hickory  bears  nuts 
whose  shell  is  easily  cracked  by  hogs,  while  another  pro- 
tects its  seeds  by  a  shell  so  hard  that  it  is  cracked  only 
by  a  pretty  heavy  blow.  In  case  of  all  such  differences, 
there  is  a  strong  tendency  to  have  the  less  eatable  fruit  or 
seed  preserved  and  allowed  to  grow,  while  the  more  eat- 
able varieties  will  be  destroyed.  Some  individuals  of  the 
European  holly  produce  bright  red  berries,  while  others 
produce  comparatively  inconspicuous  yellow  ones.  It  has 
been  found  that  the  red  berries  are  much  more  promptly 
carried  off  by  birds,  and  the  seeds  therefore  much  more 
widely  distributed  than  the  yellow  ones  are.  The  result 
of  this  kind  of  advantage,  in  any  of  its  countless  forms,  is 
sometimes  called  survival  of  the  fittest,  and  sometimes 
natural  selection.  The  latter  name  means  only  that  the 
outcome  of  the  process  just  described,  as  it  goes  on  in 
nature,  is  much  the  same  as  that  of  the  gardener's  selection, 
when,  by  picking  out  year  by  year  the  earliest  ripening 
peas  or  certain  kinds  of  the  oddest-colored  chrysanthe- 
mums, he  obtains  permanent  new  varieties.  Natural 
agencies,  acting  on  an  enormous  scale  through  many 
ages,  may  well  be  supposed  to  have  brought  about  the 
perpetuation  of  millions  of  such  variations  as  are  known 
to  be  of  constant  occurrence  among  plants,  wild  as  well 
as  cultivated. 


INDEX 


Starred  page-numbers  indicate  where  cuts  occur. 


PARTS  I  AND  II 


Absorption  of  carbon  dioxide,  166- 
170. 

Acacia,  leaf  of,  *145. 

Accessory  buds,  122,  *123. 

Accessory  fruits,  *226. 

Acuminate,  *131. 

Acute,  *131. 

Adaptations  to  conditions  of  exist- 
ence, 394. 

Adherent,  204. 

Adnate,  204. 

Adventitious  buds,  128. 

Adventitious  roots,  36. 

Aerial  roots,  36,  *37,  *38,  *39. 

Agaricus,  study  of,  264-266*. 

Age  of  trees,  71. 

Aggregate  fruits,  225,  *226. 

Ailanthus  twig,  *121. 

Air,  relation  to  germination,  10- 
12. 

Air  chamber,  *151,  *153,  *154. 

Air-passages  in  Hippurisstem,*173. 

Akene,  *222. 

Albuminous  substances,  22. 

Algae,  232,  241-257*. 

Algae,  classification  of,  *257. 

Algae,  study  of,  241-257* 


Alternate,  *65,  66. 

Alternate  leaves,  *140. 

Alternation  of  generations,  278. 

Althaea  leaf,  *152. 

Anatomy  of  plants  (see  under  root, 

stem,  leaf,  flower,  fruit,  structure 

of). 

Angiosperms,  233. 
Angiosperms,  oldest,  304,  305. 
Animal  food,  need  of,  344. 
Animals,    defenses    against,    345- 

352* 

Annual  growth,  indefinite,  69. 
Annual  ring,  *100,  *101. 
Annuals,  71. 
Anther,  201,  202,  *203. 
Anther,  modes  of  opening,  *211. 
Antheridia,  *284,  285. 
Antherozoids,  247,  248,  *251,  254, 

*279,  *284. 
Antipodal  cells,  *215. 
Ant-plants,  346,  *347. 
Ants  plant  seeds,  *386. 
Apetalous,  *198. 
Apothecia,  271. 
Apple  leaf,  stipules  of,  *135. 
Aquatic  roots,  37. 


397 


398 


FOUNDATIONS   OF   BOTANY 


Arch  of  hypocotyl,  25-27. 
Archegonia,  *284,  285,  *295. 
Arctic  willow,  *328. 
Aristolochia  stem,  bundle  of,  *88. 
Aristolochia  stem,  cross-section  of, 

*87,  88. 

Arrangement  of  leaves,  *140,  *141 . 
Arrow-shaped,  *132. 
Asci,  263,  270,  273. 
Ascomycetes,  232. 
Asexual  generation,  278. 
Ash  tree,  naturally  grafted,  *99. 
Asparagus,  79,  *80. 
Aspidium,  *288. 
Asplenium,  study  of,  286-289*. 
Assimilation,  171,  172. 
Autumn  leaves,  coloration  of,  176. 
Axillary  bud,  *122. 
Axillary  flowers,  *186. 

Bacillariales,  232. 

Bacilli,  *237. 

Bacteria,  232,  *237. 

Bacteria,  manufacture  of  nitric  acid 

by,  340. 

Bacteria,  study  of,  238,  239. 
Barbed  hairs,  *351. 
Barberry,  spiny  leaves  of,  *348. 
Bark,  86,  *91,  104. 
Basidia,  *266. 
Basidiomycetes,  232. 
Bast,  *87,  *91,  *92. 
Bast-bundle,  *92. 
Bean-pod,  study  of,  219. 
Bean  seed,  7,  8. 
Beech  twig,  64. 

Beech-wood,  cross-section  of,  *101. 
Bees,  355,  *356,  *360. 
Beet  leaf,  *151. 
Beggar's  ticks,  *384. 
Begonia  leaf,  osmose  in,  51. 


Bell-shaped,  *202. 

Belt's  bodies,  *347. 

Berry,  *225. 

Berry,  study  of,  217. 

Biennial,  47,  71. 

Biogenesis,  law  of,  299,  300. 

Birch,  branching  of,  *71. 

Bird-pollinated  flowers,  362. 

Birds  plant  seeds,  385,  *386. 

Black  mould,  study  of,  257,  258, 

259. 

Bladder-wrack,  *250. 
Botanical  geography,  324-335. 
Botanical    geography     of    United 

States,  333-335. 
Botany,  definition  of,  1. 
Box-elder,  buds  of,  *123. 
Box-elder,  radial  and  cross-sections 

of  stem  of,  *89. 
Bract,  *186,  187. 
Branches  formed  from  adventitious 

buds,  128. 

Branching,  alternate,  *65,  66. 
Branching   and    leaf-arrangement, 

64,  65. 

Branching,  opposite,  *65. 
Branch-spine,  *69. 
Brazil  nut,  food  stored  in,  23,  24. 
Breathing-pore,  *153. 
Bryophytes,  232,  277,  278. 
Buckeye,  bud  of,  *120. 
Bud,  horse-chestnut,  119,  120. 
Bud-scales,  121. 
Buds,  118-129. 
Buds,  adventitious,  128. 
Buds,  dormant,  127,  128. 
Buds,  naked,  121. 
Buds,  position  of,  121,  *122,  *123, 

*124. 

Buds,  structure  of,  119,  *125. 
Bulb,  77,  *79. 


INDEX 


399 


Bulb,  hyacinth,  *79. 

Bulb,  onion,  77. 

Bulblets,  375,  376. 

Bulrush,  cross-section  of  stem  of, 

*84. 

Burs,  381,  382,  *383. 
Buttercup,  leaf  of,  *135. 
Buttercup,  study  of  flower  of,  195. 

196. 
Butternut,  buds  of,  *124. 

Cabbage,  a  bud,  123. 

Cactus,  *80,  *315. 

Cactus  flower,  transitions  in,  *208. 

Caladium,  76,  *77. 

Calyx,  *197. 

Cambium,  *87,  *88,  *89,  95-100. 

Cambium-ring,  96,  *97. 

Canna,  parallel  veining  in,  136. 

Capsule,  223. 

Carbon  dioxide,  absorption  of,  166- 

168. 
Carbon  dioxide,  disposition  of,  168, 

169. 

Carnivorous  plants,  342-344*. 
Carpel,  198. 

Castor  bean,  germination  of,  *7. 
Castor-oil  plant,    early  history  of 

stem,  *95. 
Castor-oil      plant,      nbro-vascular 

bundle  of,  *95. 
Catharinea,  *282. 
Catkin,  *187. 
Celandine,  leaf  of,  *134. 
Cell,  20,  21. 
Cell-contents,  *19,  *155,  180,  *183, 

*184. 

Cell-contents,  continuity  of,  146. 
Cell-division,  *183,  *242,  245. 
Cell-multiplication   in   pond-scum, 

*242. 


Cell-sap,  *183. 

Cell,  simplest  form  of,  178,  *179, 

180. 

Cell-wall,  178. 
Cells,  isolated  wood-,  *91. 
Cellulose,  a  compound  of  carbon, 

hydrogen,  and  oxygen ;  the  chief 

constituent  of  ordinary  cell- walls, 

156,  171,  268. 
Central  cylinder,  *42. 
Central  placenta,  *205. 
Chara,  *248,  *249. 
Characese,  249,  250. 
Chemical  changes  in  leaves  before 

falling,  175,  176. 
Cherry,   buds   in   axils   of   leaves, 

*122. 

Cherry  twig,  *63,  *125. 
Chestnut  fruit,  *222. 
Chlorophyceae,  232. 
Chlorophyll,  168,  169,  176. 
Chlorophyll  bodies,  *154,  *155. 
Cilium,  180.  . 
Circulation   of  protoplasm,    *184, 

185. 

Cladophyll,  79,  *81. 
Class,  231. 

Classification,  228-234. 
Cleistogamous  flowers,  369,  *370. 
Clerodendron,  *363. 
Climbing  plants,  73-75*. 
Climbing    shrubs,    stem-structure, 

99,  100. 

Climbing  stems,  *73,  *74,  *75. 
Clinostat,  *58,  59. 
Clover  leaf,  *144. 
Club-moss,  study  of,  291,  *292. 
Cluster-cup,  259,  *261. 
Coherent,  200. 
Cohesion,  204,  *205. 
Collenchyma,  *95. 


400 


FOUNDATIONS   OF   BOTANY 


Colocasia,  *77. 

Coloration  of  autumn  leaves,  176. 
Colors  of  flowers,  357,  358. 
Common  receptacle,  *189. 
Compass-plant,      nearly      vertical 

leaves  of,   *147. 
Composite  head,  188,  *189,  190. 
Compound  cyme,  *191. 
Compound  leaves,  *137,  *138,  139. 
Compound  pistil,  202. 
Compound  umbel,  *189. 
Conceptacles,  250,  *252. 
Condensed  stems,  78. 
Conifers,  wood  of,  *93,  *94. 
Coniferous  wood,  structure  of,  92, 

*93,  *94. 
Conjugate,  232. 
Conjugating  cell,  *243,  *259. 
Conjugation,  *243. 
Consolidated,  204. 
Continuity  of  protoplasm,  146. 
Contractile  vacuole,  180. 
Contractility,  182. 
Cork,  90,  *100,  104,  115. 
Corm,  a  bulb-like,  fleshy  stem,  or 

base  of  stem,  "  a  solid  bulb." 
Corn,  aerial  roots  of,  *38. 
Corn,  cross-section  of  stem  of,  *83. 
Corn,  germination  of,  8. 
Corn,  grain  of,  *16.^~ 
Corn,  root- tip,  section,  *42. 
Corn-stem,  structure  of,  *83,  84. 
Corolla,  *197. 
Corymb,  *186,  187. 
Cotyledon,  7. 
Cotyledon,  disposition  made  of,  28, 

29. 

Cotyledons,  thickened,  use  of,  29. 
Crenate,  132. 
Cross-pollination,  353. 
Crow-berry,  rolled-up  leaf  of,  *317. 


Cryptogams,  231. 

Cryptogams,  classes  of,  232,  233. 

Cuspidate,  *131. 

Cuticle,  unequal  development  of,  by 

epidermis-cells,  156,  *157. 
Cutin,  156. 
Cutting  leaves,  *351. 
Cyme,  *191. 
Cypress,  71. 

Dahlia,  thickened  roots  of,  *41. 
Daily  movements  of  leaves,  *144, 

*145,  *146. 
Dandelion,  *72. 
Darwin,  Charles,  353. 
Date-palms,  *85. 
Datura,  stigma  of,  *213. 
Deciduous,  175. 

Defenses  against  animals,  345-352.* 
Definite  annual  growth,  69. 
Dehiscent  fruits,  222,  *223. 
Deliquescent  trunk,  66,  *67. 
Dentate,  132. 

Descent  of  water,  109,  *110. 
Desert,  Sahara,  *325. 
Desmids,  *243. 

Destruction  of  plants,  391,  392. 
Determinate  inflorescence,  191. 
Deutzia  leaves,  *142,  *143. 
Diadelphous,  202. 
Diagrams,  floral,  204,  *205,  *296. 
Diatoms,  study  of,  *240,  241. 
Dichogamy,  *363,  *364. 
Dicotyledonous  plants,  34,  233. 
Dicotyledonous  stem,  annual,  gross 

structure  of,  86,  *87. 
Dicotyledonous  stem,  cross-section 

of,  *87,  *89,  *91,  *96,  *100. 
Dicotyledonous  stem,    mechanical 

importance     of    distribution    of 

material  in,  89,  90. 


INDEX 


401 


Dicotyledonous  stem,  minute  struc- 
ture of,  86-98*. 

Dicotyledonous  stem,  rise  of  water 
in,  107,  108,  *109. 

Dimorphous  flowers,  *366,  367. 

Dioecious,  200. 

Discharge  of  pollen,  *211. 

Disk-flowers,  188,  *189. 

Dispersal  of  seeds,  376-386*. 

Dispersal  of  seed-plants,  373-376. 

Distinct,  201. 

Distribution  of  material  in  mono- 
cotyledonous  stems,  *84,  85. 

Dock  fruit,  study  of,  219,  220. 

Dodder,  39,  *40,  41. 

Dormant  buds,  127,  128. 

Double  flowers,  209. 

Drip-leaves,  *314. 

Drosera,  *341,  *342,  343. 

Drought,  endurance  of,  162,  163. 

Drought-plants,  313-317*. 

Dry  fruits,  224. 

Duckweed,  314. 

Duct,  *92. 

Earliest  plants,  298. 

Ecology,  2,  307. 

Egg,  osmosis  in,  50,  *51. 

Egg-cell,  *249,  *251,  280,  *284,  285. 

Elaters,  294. 

Elliptical,  *131. 

Elm,  *67. 

Elm  bud,  *125. 

Elm  fruit,  *223. 

Elm  leaf,  130,  133. 

Elm,  twig  of,  *125. 

Emarginate,  *131. 

Embryo,  6,  17. 

Embryo  sac,  *215. 

Endosperm,  *15,  *16,  17,  19. 

Energy,  source  of,  in  plants,  173. 


Enslaved  plants,  338,  *339. 
Epidermis,  uses  of,  156,  *157. 
Epidermis  of  root,  *42,  *44. 
Epigynous,  204,  *205. 
Epipetalous,  204,  *205. 
Epiphytes,  322,  *323. 
Equisetales,  232. 
Equisetum,  study  of,  292-295*. 
Essential  organs,  *197. 
Euphorbia  splendens,  *350. 
Evergreen,  175. 
Evolutionary    history    of    plants, 

298-305. 

Excretion  of  water,  172,  173. 
Excurrent  trunk,  *66. 
Existence,  struggle  for,  387-393. 
Exogenous,  96. 
Explosive  fruits,  377. 

Fall  of  horse-chestnut  leaf,  *137. 
Fall  of  the  leaf,  175,  176. 
Family,  230. 

Family,  subdivisions  of,  231. 
Fascicled  roots,  *41. 
Fermentation,  269. 
Fern,  study  of,  286-289*. 
Fern-plants,  295-297. 
Ferns,  290,  291. 
Fertilization,  *214,  *215,  216. 
Fibrous  roots,  *41. 
Fibro-vascular  bundles,  *83. 
Ficus  elastica,  leaf  of,  *154. 
Ficus  religiosa,  drip-leaf  of,  *314. 
Fig,   transpiration   in,    160,   *161, 

162. 

Filament,  201,  202,  *203. 
Filicales,  232. 
Fir  wood,  *93. 
Fission,  *242. 
Fission-plants,  232. 
Fittest,  survival  of,  394,  395. 


402 


FOUNDATIONS   OF   BOTANY 


Flax,  cross-section  of  stem  of,  *91. 

Fleshy  fruits,  224. 

Fleshy  fruits,  uses  of,  383-385. 

Fleshy  roots,  45,  40,  *47. 

Floating  seeds,  381. 

Floral  diagrams,  204,  *205,  *206. 

Floral  envelopes,  198. 

Floral  organs,  movements  of,  365, 

366. 

Florideae,  255. 

Flower,  nature  of,  208-211*. 
Flower,  organs  of,  *197. 
Flower,  plan  of,  197-206*. 
Flower-buds,  position  of,  186. 
Flowerless  plants,  232,  233,  235- 

297. 

Flowers,  bird-pollinated,  362. 
Flowers,  colors  of,  357,  358. 
Flowers,  ecology  of,  353-372*. 
Flowers,  odors  of,  357. 
Flytrap,  Venus,  *343,  344. 
Follicle,  *223. 
Food  in  embryo,  14. 
Food,  storage  of,  in  root,  46,  *47. 
Food,  storage  of,  in  stem,  113-117. 
Food,  storage  outside  of  embryo, 

15. 

Formative  tissue,  95. 
Fossil  plants,  298,  299. 
Fossils,  298. 
Four-o'clock  seed,  15. 
Foxglove,  pinnate  leaf  of,  *133. 
Free,  204. 

Free  central  placentation,  *205. 
Frond,  287,  *288. 
Frost,  action  of,  394. 
Fruit,  221-227*. 
Fruit,  definition  of,  221. 
Fruit-dots,  *288. 
Fruits,  study  of,  217-220. 
Fruits,  uses  of,  376-386*. 


Fucus,  250-252*. 
Funaria,  *284. 
Fungi,  232,  274-276. 

Gametophyte,  291. 

Gamopetalous,  200. 

Gamosepalous,  200. 

Gemmae,  279. 

Generations,  alternation  of,  278. 

Generative    cells,    in    pollen  tube, 

*214. 

Genus,  229. 

Geography,  botanical,  324-335. 
Geography,  botanical,  of  the  United 

States,  333-335. 
Geotropism,  *57,  *58,  59,  68. 
Germination,  5-13. 
Germination,     chemical      changes 

during,  11-13. 

Germination,  conditions  of,  8-11. 
GUIs,  *264,  265. 
Gonidia,  273. 
Gourd-fruit,  224. 
Grafting,  98,  *99. 
Grain,  222. 

Grape  sugar,  test  for,  116,  117. 
Gray,  Asa,  71. 
Green  layer  of  bark,  86,  *91. 
Groups,  231. 
Growing  point,  *42. 
Growth,  measurement  of,  in  stem, 

32. 

Growth,  secondary,  *96,  *97,  *100. 
Guard-cells,  *151,  *153,  *154,  158, 

159. 
Gymnosperms,  233. 

Haematococcus,  *244. 
Hairs,  158. 

Hairs,  stinging,  349,  350,  *351. 
Halberd-shaped,  *132. 


INDEX 


403 


Half-parasites,  336. 

Halophytes,  311,  *319,  320,  *326. 

Hard  bast,  *87,  *91,  *92. 

Haustoria,  39. 

Head,  *188. 

Heart-shaped,  *132. 

Heartwood,  105. 

Heliotropism,  148. 

Hemlock,  lateral  extension  of 
roots,  *60. 

Hepaticse,  232,  280,  281. 

Hepaticse,  study  of,  278-280*. 

Herbs,  70. 

Hesperidium,  *225. 

High  mallow,  provisions  for  cross- 
pollination  of,  *364. 

Hilum,  6. 

Honey-bee,  leg  of,  *356. 

Honey-gland,  *357. 

Honey  locust,  spine,  *69. 

Hop,  twining  of,  *75. 

Hormogonia,  *238. 

Horse-chestnut  bud,  study  of,  119, 
120. 

Horse-chestnut,  germination,  8. 

Horse-chestnut  twig,  62-64. 

Host,  39. 

Hot  springs,  plants  in,  393. 

Hyacinth,  bulb  of,  *79. 

Hybrid,  229. 

Hybridization,  229. 

Hydrangea,  transpiration  in,  159- 
161* 

Hydrogen,  168. 

Hydrophytes,  311,  *312,  *313, 
*314. 

Hymenium,  *265. 

Hyphae,  257,  *258. 

Hypocotyl,  6,  25-27. 

Hypocotyl,  cross-section  of,  95. 

Hypogynous,  204,  *205. 


Iceland  moss,  274. 
Imperfect  flowers,  199. 
Indefinite  annual  growth,  69. 
Indehiscent  fruits,  221,  *222. 
Indeterminate  inflorescence,  186. 
Indian  corn,  germination  of,  8. 
Indian  corn,  kernel  of,  16. 
Indian  corn,  root-tip,  *42,  ^3. 
Indian    corn,    structure    of    stem, 

*83,  84. 

Indian  pipe,  169. 
India-rubber  plant,  leaf  of,  *154. 
India-rubber    plant,    transpiration 

of,  160-162. 
Indusium,  287,  *288. 
Inflorescence,  186-191*. 
Inflorescence,  determinate,  191. 
Inflorescence,  diagrams  of,  *190. 
Inflorescence,  indeterminate,  186. 
Insectivorous  plants,  340-344*. 
Insect  pollination,  355-369* 
Insect  pollination,  study   of,  367- 

369. 
Insects,  pollen-carrying  apparatus 

of,  355,  *356. 

Insects,  sense  of  smell  of,  357. 
Insects,  vision  of,  358. 
Insect-traps,  leaves  as,  *342,  *343. 
Insect  visits,  358-362*,  *365. 
Insertion  of  floral  organs,  *205. 
Intercellular  spaces,  *95. 
Internode,  32,  83. 
Involucre,  188,  *189. 
Ipomcea  Jalapa,  46. 
Ipomcea,  rate  of  increase  of,  390, 

391. 

Iris,  rootstock  of,  *77. 
Irish  moss,  253. 
Irritability  in  plants,  nature   and 

occurrence  of,  182-184. 
Ivy,  aerial  roots  of,  *39. 


404 


FOUNDATIONS   OF   BOTANY 


Keel,  *199. 
Kidney-shaped,  *131. 
Knots,  *102. 

Labiate,  *203. 

Ladyfern,  286. 

Lanceolate,  *131. 

Lateral  buds,  63,  121. 

Leaf,  130-139*. 

Leaf,  accumulation  of  mineral 
matter  in,  165. 

Leaf-arrangement,  *140,*141,  *142, 
*143. 

Leaf-bases,  *132. 

Leaf-buds,  122,  123. 

Leaf,  fall  of,  175,  176. 

Leaf-like  stems,  78,  79,  *81. 

Leaf-margins,  *132. 

Leaf-mosaics,  142,  *143. 

Leaf-outlines,  *131. 

Leaf-sections,  *151,  *154. 

Leaf-spine,  *348. 

Leaf-stalk,  130. 

Leaf-tendril,  *138. 

Leaf-tips,  *131. 

Leaf -traces,  155. 

Leaves  as  insect-traps,  *342,  *343. 

Leaves,  compound,  *137,  *138, 139. 

Leaves  cutting,  350,  *351. 

Leaves,  divided,  143. 

Leaves,  functions  of,  155-174. 

Leaves,  movements  of,  *144,  *145, 
*146. 

Leaves,  simple,  137. 

Leaves,  structure  of,  150-158*. 

Legume,  223. 

Lemon,  study  of,  217,  218. 

Lenticels,  104. 

Leucoium,  pollen  tube  with  gener- 
ative cells,  *214. 

Lianas,  *73. 


Lichen,  232. 

Lichenes,  232. 

Lichens,  nature  of,  273,  274. 

Lichens,  study  of,  270-273*. 

Light,  exposure  to,  140-149*. 

Light,   movements    towards,    148, 

149. 

Lignin,  171,  172. 
Lily  leaf,  150. 
Lily,  pollen  grains  producing  tubes 

on  stigma,  *214. 
Limb  of  calyx  or  corolla,  200. 
Lime,  165. 

Linden,  fruit  cluster  of,  *377. 
Linden  fruit,  *377. 
Linden  wood,  structure  of,  *100. 
Linear,  *131. 
Liverworts,  277-281*. 
Living  parts  of  the  stem,  104,  105. 
Lobe,  201. 
Locules,  203. 
Locust,  pinnately   compound  leaf 

of,  *138. 

Locust,  thorn-stipules  of,  350. 
Luffa,  86. 
Lupine,  white,  8. 
Lycopodiales,  232. 
Lycopodium,  study  of,  291,  *292. 

Macrospores,  291,  *302. 

Macrosporophyll,  302. 

Magnolia,  forking  of,  *70,  *71. 

Mahogany  wood,  structure  of,  *101. 

Maldive  nut,  381. 

Mallows,  pollination  in,  364. 

Malt,  13. 

Maltose,  116. 

Mangrove,  *319. 

Maple  fruit,  *223. 

Maple  leaf,  134. 

Marchantia,  study  of,  278-281*. 


INDEX 


405 


Marestail,  air-passages  of,  *173. 
Mechanics    of     monocotyledonous 

steins,  *84,  85. 
Medullary  ray,  45,  *101. 
Melon,     palmately     netted-veined 

leaf  of,  *133. 
Melon-cactus,  78,  *80. 
Messmates,  340. 
Mesophytes,  317,  318. 
Mesquite,  root-system  of,  48. 
Metabolism,  165-176. 
Metabolism,  digestive,  172. 
Micropyle,  6. 

Microsphsera,  study  of,  263,  264. 
Microspores,  *302. 
Microsporophyll,  302. 
Midrib,  *133. 

Mildews,  powdery,  263,  *264. 
Mimicry,  347,  348. 
Mineral  matter  accumulated  in  the 

leaf,  165. 
Mistletoe,  337. 
Modified  leaves,  121. 
Moisture-plants,  311-313. 
Monadelphous,  202,  *204. 
Monocotyledonous  plants,  34,  233. 
Monocotyledonous  stems,  *83,  *84, 

*85,  86. 
Monocotyledonous  stems,   growth 

of,  in  thickness,  85,  86. 
Monocotyledonous  stems,    rise   of 

water  in,  *110. 
Monocotyledons,  233. 
Moncecious,  200. 
Monotropa,  169. 
Morning-glory,  rate  of  increase  of, 

390,  391. 

Morphology,  1,  33. 
Moss,  study  of,  281-285. 
Mosses,  281-285*. 
Moths,  *361,  362. 


Mould,  black,  study  of,  257,  258, 

259. 
Movement  of  water  in  plants,  107, 

*108,  *109,  *110,  111,  112,  113. 
Movements  of  floral  organs,  *365, 

*366. 
Movements  of  leaves,  *144,  *145, 

*146. 

Movements  toward  light,  148. 
Mucronate,  *131. 
Mulberry,  *226. 
Mullein,    hairs    from    corolla    of, 

*361. 

Multiple  fruits,  *226. 
Multiple  primary  roots,  14. 
Musci,  232. 

Mushroom,  study  of,  264-266*. 
Mutilated  seedlings,  growth  of,  14. 
Mycelium,  257,  *258. 
Mykorhiza,  342. 
Myrsiphyllum,  79,  *81. 
Myxogasteres,  232. 
Myxothallophytes,  232,  233. 

Naked  buds,  121. 

Nasturtium  leaves,  starch  in,  *170. 

Natural  selection,  394,  395. 

Nectar,  356. 

Nectar-glands,  356. 

Nectar-guides,  358. 

Nectaries,  357. 

Negundo,  radial  and  cross-sections 

of  stem  of,  *89. 

Nemalion,  study  of,  253,  254,  *255. 
Netted-veined,  *133. 
Nettle,  stinging  hair  of,  *184. 
Nightshade,  leaf  of,  *349. 
Nitella,  study  of,  247-250. 
Nitrogen,  171,  340. 
Nocturnal  position,  *144,  *145, 
Node,  31,  32,  83. 


406 


FOUNDATIONS   OF   BOTANY 


Nucleus,  178. 

Nucleus  of  root-hair,  *49. 

Nut,  *222,  223. 

Nutrient  substances,  168,  169,  171. 

Nutrition  of  plants,  165-176. 

Oak  leaves,  arrangement  of,  *140. 

Oat,  root-system  of,  48. 

Obovate,  *131. 

Obtuse,  *131. 

Odors  of  flowers,  357. 

Offensive-smelling  plants,  352. 

Oil,  21,  22. 

Oil,  essential,  24. 

Oil,  extraction,  22. 

Oil,  testing  seeds  for,  21,  22. 

Onion,  bulb  of,  77. 

Onion  leaf,  section  of,  *79. 

Onion,  structure  of,  116. 

Onion,  tests  for  food-materials  in, 

116,  117. 
Oogonia,  *251. 
Oosphere,   *249,    *251,   280,   *284, 

285. 

Oospore,  247,  249. 
Opposite,  *65,  *140,  *141,  *142. 
Orbicular,  *131. 
Orchid,  aerial  roots  of  an,  *37. 
Order,  230. 

Organs,  essential,  *197. 
Organs,  vegetative,  30. 
Oscillatoria,  study  of,  239,  240. 
Osmosis,  50-54. 
Osmosis  in  an  egg,  50,  *51. 
Osmosis  in  root-hairs,  53,  54. 
Ovary,  201,  202,  *203,  *205. 
Ovate,  *131. 
Ovoid,  egg-shaped. 
Ovule,  202,  *203. 
Ovule,  spruce,  fertilized,  *303. 
Ovule,  structure  of,  *215. 


Oxalis  leaf,  development  of,  *127. 
Oxidation,  11,  12. 
Oxygen,  11,  12,  166,  167,  168. 
Oxygen-making,  167,  168. 

Palisade-cells,  *151. 

Palmate,  *133. 

Pampas  region,  393. 

Panicle,  *189,  190. 

Panicum,  *381. 

Pansy,  leaf-like  stipules  of,  *135. 

Papilionaceous  corolla,  *199. 

Papillae  on  stigma  of  a  lily,  *214. 

Paraphyses,  251,  *252. 

Parasites,  39,  336-338. 

Parasitic  roots,  39,  *40. 

Parenchyma,  94. 

Parietal  placenta,  203,  *205. 

Parsnip  root,  study  of,  45,  46. 

Pea  seed,  8. 

Pea  seedling,  mutilated,  14. 

Pea  seedling  on  clinostat,  58. 

Peat  bogs,  327. 

Peat  moss,  *327. 

Pedicel,  *186,  187. 

Peduncle,  *186,  187. 

Peg  of  squash  seedling,  27. 

Pepo,  224. 

Perennial,  47,  71. 

Perfect,  198. 

Perianth,  *197. 

Pericarp,  224. 

Perigynous,  204,  *205. 

Perithecia,  263. 

Permanganate  test,  28. 

Petal,  197. 

Petiole,  130,  134. 

Phseophycese,  232. 

Phanerogams,  231,  233. 

Phanerogams,  classes  of,  233. 

Phosphorus,  165. 


INDEX 


407 


Phycomycetes,  232. 

Physcia,  270-273. 

Physiology,  vegetable,  1. 

Pigeon-wheat  moss,  study  of,  281- 
285. 

Pileus,  *264,  265. 

Pine,  seedling,  *33. 

Pine  wood,  *94. 

Pinnae,  leaflets  of  a  pinnately  com- 
pound leaf,  138. 

Pinnate,  *133. 

Pinnules,  *288. 

Pistil,  *197,  201,  202,  *203. 

Pistil,  parts  of,  *203. 

Pitcher-plant,  *340. 

Pith,  *83,  *87,  *88,  *89. 

Placenta,  203,  *206. 

Plankton,  333. 

Plant  colonies,  310. 

Plant  formations,  310. 

Plant  physiology,  definition  of,  1. 

Plant  societies,  307-323,  *312,*322. 

Plants  of  uneatable  texture,  348. 

Plants,  classes  of,  in  relation  to 
economy  of  water,  311. 

Plants,  destruction  of,  by  animals, 
345. 

Plants,  earliest  appearance  of,  298. 

Plants,  mimicry  by,  347,  348. 

Plasmolysis,  52,  53. 

Pleurococcus,  study  of,  244,  245. 

Plumule,  7. 

Pod,  219,  223. 

Poisonous  plants,  352. 

Poisonous  seeds,  24. 

Poisons,  plants  containing,  352. 

Pollarded  trees,  128. 

Pollen,  201,  211,  *212. 

Pollen-carrying  apparatus,  355, 
366. 

Pollen,  discharge  of,  *211. 


Pollen  grains,  *212. 

Pollen     grains,     number    of,    per 

ovule,  216. 
Pollen,  protection  of,  from  visitors, 

360-362. 
Pollen,  protection  of,    from   rain, 

*371,  372. 

Pollen  tubes,  212,  213,  *214. 
Pollination,  353-355. 
Polypetalous,  201. 
Polysepalous,  201. 
Polysiphonia,  255. 
Polytrichum,  281-285. 
Pome,  224. 

Pond-scum,  study  of,  241-244*. 
Potash  in  hay,  165. 
Potato  tuber,  76,  *78,  114-116. 
Prickle,  *349. 
Prickly  leaves,  *349. 
Prickly  pear,  *315. 
Primary  root,  36. 
Primrose,  pollination  in  flowers  of, 

*366,  367. 
Procainbium,  *96. 
Prosenchyma,  94,  95. 
Propagation,  by  root,  61. 
Propagation,     means    of,     among 

cryptogams,  373. 
Propagation  of  plants,  373-386*. 
Protection  of  plants  from  animals, 

345-352. 
Protection   of    pollen    from    rain, 

*371,  372. 
Proteids,  22,  23. 
Proteids,  tests  for,  23. 
Prothallium,  287,  *289. 
Protococcus,  *244. 
Protonema,  283. 
Protoplasm,  52,  178. 
Protoplasm,  characteristics  of,  181, 

182. 


408 


FOUNDATIONS   OF  BOTANY 


Protoplasm,    circulation   of,    *184, 

185. 

Protoplasm,  continuity  of,  146. 
Pteridophytes,  232. 
Pteridophytes,   remarks    on,    286, 

295-297. 

Puccinia,  study  of,  259-262*. 
Pulvini,  145,  *146. 

Race,  230. 
Raceme,  *186. 
Raspberry,  *374. 
Ray,  medullary,  45. 
Ray-flowers,  188,  *189. 
Receptacle,  199. 
Red  clover,  leaf  of,  *144. 
Regions  of  vegetation,  324. 
Regular  flowers,  198. 
"  Reindeer  moss,"  274. 
Reproduction  in  algse,  256. 
Reproduction  in  ferns,  287,  *288, 

*289,  291. 
Reproduction  in  flowering  plants, 

212-215*. 
Reproduction  in  fungi,  *258,  *259, 

*260,    *261,    *262,    *265,    *266, 

*268,  *270. 
Reproduction    in    morning-glory, 

390,  391. 

Reproduction  in  mosses,  *284,  285. 
Resin  passage,  *93. 
Respiration,  172,  173. 
Retuse,  *131. 
Rhachis,  287,  *288. 
Rhizoids,  hairs  serving  as  roots  in 

mosses    and    liverworts,    *282, 

*289. 

Rhizopus,  study  of,  257,  258,  259. 
Rhodophycese,  232. 
Rhubarb  roots,  *47. 
Ring,  annual,  *100,  *101. 


Ringent,  *203. 

Rise  of  water  in  stems,  108-113. 

Rockweed,  study  of,  250-252*. 

Root,  36-61. 

Root,  adaptation  to  work,  59,  60. 

Root-cap,  *42. 

Root-climbers,  *39,  73. 

Root,  dicotyledonous,  section,  *44. 

Root,  elongation  of,  30,  31. 

Root,  exogenous,  *44. 

Root,  fleshy,  45,  46,  *47. 

Root-hair,  31,  *32,  *49,  50. 

Root-pressure,  54,  *55. 

Root-section,  *42,  *44. 

Root-sheath  or  root-pocket,  37. 

Root-system,  47,  48. 

Roots,   absorbing   surface  of,   49, 

.    50. 

Roots,  absorption  and  temperature, 

55,  56. 

Roots,  adventitious,  36. 
Roots,  aerial,  36,  *37,  *38,  *39. 
Roots,  brace-,  *38. 
Roots,  fascicled,  *41. 
Roots,  fibrous,  *41. 
Roots,  growth  of,  30,  31. 
Roots,  hemlock,  lateral  extension 

of,  *60. 
Roots,   movements   of  young,   56, 

*57,  *58,  59. 
Roots,  parasitic,  39,  *40. 
Roots,  primary,  36. 
Roots,  propagation  by,  61. 
Roots,  selective  action  of,  54. 
Roots,  soil-,  36. 
Roots,  storage  of  nourishment  in, 

46,  *47. 

Roots,  structure  of,  41-46. 
Roots,  water,  37. 
Rootstock,  75,  *76,  *77. 
Rotation  of  protoplasm,  *184,  185. 


INDEX 


409 


Round-leafed  mallow,  stamens  and 

pistils  of,  364. 
Russian  thistle,  *379. 
Russian  thistle,  spread  of,  394. 
Rust,  259. 

Rust,  wheat,  study  of,  259-262*. 
Rye  grass,  76. 

Sage,    pollination    in    flowers    of, 

*365,  *366. 
Sago-palm,  113. 
Salver-shaped,  *202. 
Salvinia,  *302. 
Sap,  descent  of,  *109,  110. 
Sap,  rise  of,  107,  108,  *109. 
Saprophytes,  169,  269. 
Sapwood,  105. 
Scalloped,  *132. 
Schizomycetes,  232. 
Schizophycese,  232,  *238. 
Scirpus,  cross-section  of  stem  of, 

*84. 

Sclerenchyma,  84. 
Scouring-rush,  study  of,  292-295*. 
Seasonal  plants,  311. 
Secondary  growth,  *96,  *97,  *100. 
Secondary  root,  36. 
Secondary  roots,  direction  of,  59. 
Sections,  leaf,  *151,  *154. 
Sections,  root,  *42,  *44. 
Sections,  wood,  *100,  *101,  *102. 
Sedge,  rootstock  of,  *76. 
Seed,  5-24. 
Seed-leaf,  *6,  7. 
Seedlings,  25-35. 

Seedlings,  mutilated  growth  of,  14. 
Seed-plants,  231,  233. 
Seed-plants,  classes  of,  233. 
Seeds,  containing  poisons,  24. 
Seeds,  dispersal  of,  377-386*. 
Selection,  natural,  395. 


Selective  absorption,  53,  54. 

Self-pollination,  353. 

Sepal,  197. 

Separated  flowers,  199,  200,  *201. 

Sequoia,  *66,  71,  *106.  . 

Series,  plants  form  a,  300. 

Serrate,  *132. 

Sexual  generation,  278. 

Shade  plants,  *321. 

Shoot,  30. 

Shrubs,  69,  70. 

Sieve-cells,  *93,  110. 

Sieve-plate,  *93. 

Sieve-tubes,  *93. 

Silica,  165,  241,  294. 

Simple  leaves,  137. 

Simple  pistil,  202. 

Simple  umbel  of  cherry,  *187. 

Sinuate,  *132. 

Sleep  of  leaves,  *144,  *145. 

Slime-fungi,  232. 

Slime  moulds,  178,  *179,  180,  181, 

*236,  237. 
"Smilax,"  79,  *81. 
Snowflake,    pollen    tube   of,   with 

generative  cells,  *214. 
Solomon's  seal,  parallel-veined  leaf 

of,  *136. 
Soredia,  271. 
Sori,  261,  287,  *288. 
Spatulate,  *131. 
Species,  229. 
Spermagones,  271. 
Spermatia,  271. 
Spike,  188. 

Spine,  *347,  *348,  *350. 
Spiral  vessel,  *92. 
Spirogyra,  study  of,  241,  242,  *243, 

244. 

Sporangium,  287,  *288. 
Spore,  235,  *236. 


410 


FOUNDATIONS   OF   BOTANY 


Spore-capsules,  281. 

Spore-cases,  *258,  *259. 

Spore-fruits,  *254. 

Spore-plants,  231,  232. 

Spore-plants,  classes  of,  232. 

Spore-sacs,  263,  270,  273. 

Spores  of  slime  moulds,  180. 

Sporophyll,  294. 

Sporophyte,  281,  *282,  284,  285, 
289,  291. 

Spruce,  fertilized  ovule  of,  *303. 

Squash  seed,  5,  6. 

Squash  seed,  section,  *6. 

Squash  seedling,  25-27. 

Stamen,  *197,  201,  202,  *203. 

Stamen,  parts  of,  *203. 

Standard,  *199. 

Starch,  17-20,  *19. 

Starch  disappears  during  germi- 
nation, 21. 

Starch  in  leaves,  169,  *170. 

Starch-making,  rate  of,  170,  171. 

Starch,  testing  seed  for,  18. 

Stem,  30-117. 

Stem,  definition  of,  62. 

Stem,  dicotyledonous,  annual, 
gross  structure  of,  86,  *87. 

Stem,  dicotyledonous,  minute 
structure  of,  86-98*. 

Stem,  early  history  of,  *95,  96. 

Stem,  functions  of  cells  of,  105, 
106,  107. 

Stem,  modifiability  of,  79-82*. 

Stem,  monocotyledonous,  *83,  *84, 
*85,  86. 

Stem,  structure  of,  83-103*. 

Stemless  plants,  *72,  73. 

Stems,  62-118. 

Stems,  climbing,  74,  *75. 

Stems,  storage  of  food  in,  113-115. 

Stems,  twining,  *75. 


Stem-structure,  early  history  of, 
*95,  96. 

Sterigmata,  *266. 

Sterilization,  238. 

Stigma,  201,  *203. 

Stigma,  structure  of,  213-215*. 

Stinging  hair,  *184. 

Stipa.  cross-section  of  rolled  and 
unrolled  leaves  of,  *318. 

Stipe,  *264,  265. 

Stipules,  *135,  136. 

Stolon,  with  tips  rooting,  *374. 

Stomata,  104,*151,  *152,*153,*154. 

Stomata,  operation  of,  158,  159. 

Stone-fruit,  224. 

Storage  of  food  in  the  root,  46,  *47. 

Storage  of  food  in  the  stem,  113- 
117. 

Strawberry,  *226. 

Struggle  for  existence,  387-394. 

Study  of  buttercup  flower,  195,  196. 

Study  of  lemon,  217,  218. 

Study  of  tomato,  217. 

Study  of  trilliuin  flower,  192,  193. 

Study  of  tulip  flower,  194,  195. 

Style,  201,  *203. 

Sugar,  13,  116,  .117,  168,  171,  172. 

Sugar,  formed  during  germination, 
13. 

Sugar-cane,  cross-section  of  a  bun- 
dle from,  *110. 

Sundew,  *341,  *342,  343. 

Sun-plants,  *321. 

Supernumerary  buds,  122,  *123, 
*124. 

Survival  of  the  fittest,  394,  395. 

Swarmspores,  180. 

Sweet  pea,  flowers,  *199. 

Symbiont,  340. 

Symbiosis,  273,  340. 

Symmetrical,  198. 


INDEX 


411 


Taper-pointed,  *131. 

Taproot,  *41. 

Teleutospores,  *262. 

Temperature  and  root-absorption, 
55,  56. 

Temperature,  relation  to  germina- 
tion, 9. 

Tendril,  *138. 

Tendril  climbers,  *74. 

Terminal  bud,  63,  121,  122,  *124, 
*125. 

Terminal  flowers,  186,  *191. 

Tertiary  root,  36. 

Testa,  6. 

Tetraspores,  *255. 

Thallophytes,  232,  235-275. 

Thallophytes,  study  of,  237-273*. 

Thallus,  235,  250. 

Thermostat,  9. 

Thistle,  Russian,  *379,  394. 

Thorns  as  branches,  68,  *69. 

Thyme,  stoma  of,  *153. 

Tickle-grass,  *381. 

"Timber  line,"  *329,  *330. 

Tissue,  94,  95. 

Tomato,  study  of,  217. 

Tracheids,  92,  93,  *94. 

Transition  from  stamens  to  petals, 
*209. 

Transpiration,  156. 

Transpiration,  amount  of,  164, 165. 

Transpiration,     measurement     of, 
159,  *160,  161. 

Transportation  by  water,  380,  381. 

Trees,  69. 

Trees,  age  of,  71. 

Trillium,  study  of  flower  of,   192, 
193. 

Trimorphous  flowers,  367. 
Tropseolum  leaf ,  *132. 
Tropseolum  leaves,  starch  in,  *170. 


Tropaeolum,  petiole,  coiling  of,*  75. 

Tropical  vegetation,  324,  325. 

Tropophytes,  311,  318,  319. 

Truncate,  *131. 

Trunk,  *66,  *67. 

Tuber,  76,  *78. 

Tubercles  on  clover  roots,  *339. 

Tubular  corolla,  *203. 

Tulip,  study  of  flower  of,  194,  195. 

Tumble-weeds,  378,  *379,  *380. 

Turgescence,  184. 

Turnip,  seedling,  *32. 

Twayblade,    beetle   on  flower  of, 

*359. 

Twigs,  study  of,  62-64. 
Twiners,  74,  *75. 
Twining,  rate  of,  74,  75. 
Types,    order   of    appearance    of, 

298-305. 

Umbel,  *187. 

Umbellet,  190. 

Underground  stems,  75,  *765  *77, 

*78,  *79. 

Uneatable  plants,  348. 
Union  of  pistils,  202,  203. 
Union  of  stamens,  201,  202. 
Uredospores,  261,  *262. 
Usnia,  *271. 

Vacuole,  contractile,  180. 

Variety,  229,  230. 

Vaucheria,    study    of,    245,  *246, 

247. 

Vegetable  physiology,  1. 
Vegetation,  alpine,  328,  *329,  *330, 

*331. 

Vegetation,  aquatic,  332,  333. 
Vegetation,  arctic,  327,  *328. 
Vegetation,  regions  of,  324. 
Vegetation,  temperate,  325,  326. 


412 


FOUNDATIONS   OF   BOTANY 


Vegetation,  tropical,  324,  325. 
Vegetative  organs,  30. 
Vein,  130,  *133,  *136. 
Veining,  *133,  *136. 
Venation,  *133,  134,  135,  *136. 
Venus  flytrap,  *343,  344. 
Vernation,  125,  *126,  127. 
Vertically  placed  leaves,  146,  *147, 

148. 

Vessel,  *92,  106. 
Volva,  *265. 

Water,  absorption  by  roots,  53-55. 
Water,    amount   transpired,    159- 

165. 
Water,  course  through  leaf,  163, 

164. 

Water,  excretion  of,  172,  173. 
Water,  movement   of,    107,   *108, 

*109,  *110,  111,  112,  113. 
Water,  relation  to  germination,  10. 
Water-lily,      white,     insertion    of 

floral  organs,  *205. 
Water-lily,  white,  transitions  from 

petals  to  stamens  in,  *209. 
Water  roots,  37. 
Weapons  of  plants,  349-351*. 
Wedge-shaped,  *131. 
Weeds,  387-390. 
Weeds,  study  of,  388,  389. 
Wheat-grain,  section  of,  *19. 


Wheat  rust,  study  of,  259-262*. 

Wheel-shaped,  *202. 

Whorled,  *293,  294. 

Willow,  adventitious  buds  of,  128. 

Willow,  arctic,  *328. 

Willow,  flowers  of,  *201. 

Wilting,  111. 

Wind-pollination,  354. 

Windsor  bean  sprouting  over  mer- 
cury, 56,  *57. 

Winged  fruits,  377,  *378. 

Wings,  *199. 

Wood,  coniferous,  structure  of,  92, 
*93,  *94. 

Wood  of  linden,  *100. 

Wood  sections,  *100,  *101,  *102. 

Wood,  structure  of,  *93,  *100, 
*101. 

Wood-cell,  *89,  *91,  *101. 

Wood-parenchyuia,  94. 

Xanthoria,  *271. 
Xerophytes,  311,  313-317*. 

Yarrow,  head  of,  *189. 
Yeast,  study  of,  266-270,  *268. 
Yucca,  335. 

Zones,  vegetation  of,  324-328. 
Zoospores,  236,  *244. 
Zygospores,  236,  *243,  *259. 


BERGEN'S     BOTANY 


KEY  AND  FLORA 


NORTHERN  AND    CENTRAL    STATES 
EDITION 


BY 


JOSEPH   Y.  BERGEN,  A.M. 

INSTRUCTOR  IN  BIOLOGY,  ENGLISH  HIGH  SCHOOL,  BOSTON 


BOSTON,  U.S.A. 
GINN  &  COMPANY,  PUBLISHERS 


1901 


COPYRIGHT,  1901 
BY  JOSEPH  Y.  BERGEN 


ALL  BIGHTS  KESEEVED 


PREFACE 

THIS  flora  furnishes  a  key  to  the  commoner  spring-flower- 
ing families  of  Phanerogams  and  descriptions  of  the  charac- 
teristics of  these  families,  together  with  such  genera  and 
species  under  each  as  seem  most  available  for  school  study  in 
the  central  and  northeastern  states.  The  descriptions  have 
been  in  part  compiled  by  the  author  from  various  sources, 
and  in  part  written  with  the  plants  themselves  in  hand.  The 
characterizations  of  many  families  and  of  some  genera  are 
taken  with  slight  simplifications  from  Hooker's  Student's 
Flora  of  the  British  Islands;  a  few  are  from  Warming's 
Systematic  Botany.  The  remainder  are  mostly  adapted  from 
the  floras  of  Gray  and  Wood,  from  Sargent's  Silva  of  North 
America,  and  from  Britton  and  Brown's  illustrated  Flora  of 
the  Northern  States  and  Canada. 

The  sequence  of  the  families  (and  sometimes  the  genera 
under  their  respective  families)  is  based  on  Engler's  Syllabus 
der  Pflanzenfamilien,  which  has  also  been  followed  as  regards 
nomenclature  of  families.  In  other  regards  the  sixth  edition 
of  Gray's  Manual,  and  Bailey's  revision  of  Gray's  Field,  Forest, 
and  Garden  Botany  have  been  followed  as  authorities.  Valu- 
able information  concerning  the  precise  time  of  flowering  of 
many  species  has  been  derived  from  Darlington's  Flora  Cestrica 
and  Ward's  Guide  to  the  Flora  of  Washington  and  Vicinity. 

By  arrangement  with  Professor  S.  M.  Tracy  a  considerable 
portion  of  the  key  and  a  large  number  of  the  following 
descriptions  have  been  copied  (a  little  simplified)  from  his 
Flora  of  the  Southeastern  States  ;  these  are  designated  by  an 
asterisk  at  the  end  of  each  description. 

1 


2  PREFACE 

Especial  acknowledgments  are  due  to  Professor  Benjamin 
L.  Bobinson,  Director  of  the  Gray  Herbarium  of  Harvard 
University,  who  has  given  most  valuable  advice  and  has 
revised  the  manuscript  of  the  keys  and  flora,  thus  contribut- 
ing greatly  to  any  value  which  they  may  be  found  to  possess. 

Much  aid  has  been  derived  from  the  careful  proof-reading 
of  Professor  J.  M.  Holzinger  of  the  Minnesota  State  Normal 
School,  Professor  L.  H.  Pammel  of  the  Iowa  State  College, 
and  Miss  Mary  P.  Anderson  of  the  Somerville,  Mass.,  English 
High  School.  The  author  wishes  heartily  to  thank  these 
critics  for  the  many  errors  which  they  have  corrected  and 
the  valuable  additions  which  they  have  suggested. 

The  territory  covered  overlaps  that  dealt  with  by  Professor 
Tracy  in  the  flora  above  cited,  and  nearly  meets  that  embraced 
in  Miss  Eastwood's  Flora  of  the  Rocky  Mountains  and  the 
Salt  Lake  Basin,  since  many  of  the  species  treated  in  the 
present  work  range  west  as  far  as  the  hundredth  meridian. 

The  plants  chosen  to  constitute  this  flora  are  those  which 
bloom  during  some  part  of  the  latter  half  of  the  ordinary 
school  year,  and  which  have*  a  rather  wide  territorial  range. 
Enough  forms  have  been  described  to  afford  ample  drill  in 
the  determination  of  species.  Gray's  Manual  of  Botany  or 
Field,  Forest,  and  Garden  Botany  will  of  course  be  employed 
by  the  student  who  wishes  to  become  familiar  with  most  of 
the  seed-plants  of  the  region  here  touched  upon.  Those 
species  which  occur  in  the  central  and  northeastern  United 
States  only  as  cultivated  plants  are  so  designated.  The  illus- 
trations are  mainly  redrawn  from  German  sources.  A  few 
of  them  are  the  work  of  Mr.  E.  N.  Fischer  of  Boston,  but 
the  greater  portion  are  by  Dr.  J.  W.*Folsom  of  the  Illinois 

Industrial  University. 

J.  Y.  B, 

CAMBRIDGE,  MASS.,  January,  1901. 


HOW  TO  USE  THE  KEY  AND  FLORA 


IN  order  to  determine  an  unknown  species,  the  student  is 
first  to  make  a  careful  examination  of  the  plant  in  hand. 
After  noting  in  a  general  way  the  appearance  of  the  root, 
stem,  and  leaf,  including  a  cross-section  of  the  stem,  he 
should  study  the  number,  coherence,  and  adnation  of  the 
parts  of  the  flower,  then  make  and  draw  a  cross-section  and 
a  lengthwise  section  of  it.  Irregularities  in  calyx  or  corolla, 
peculiarities  in  the  shape,  structure,  or  operation  of  the  essen- 
tial organs,  such,  for  instance,  as  anthers  discharging  through 
chinks  in  the  end,  should  be  noted. 

Next,  the  inquirer  should  look  carefully  through  the  Key 
to  the  families.  He  is  first  to  decide  whether  the  plant  in 
question  is  a  Gymnosperm  or  an  Angiosperm;  if  not  a  conif- 
erous tree  or  shrub,  it  will  of  course  belong  to  the  latter 
division.  He  is  then  to  settle  the  question  whether  it  is  a 
Monocotyledon  or  a  Dicotyledon ;  then  under  what  division  of 
the  group  the  plant  comes ;  and,  finally,  to  decide  upon  its 
family. 

Turning  now  to  the  page  at  which  the  family  is  described, 
a  rapid  inspection  of  the  characteristics  of  the  genera  will 
make  it  evident  to  which  one  the  species  under  examination 
belongs.  It  may  not  infrequently  prove  that  none  of  the 
genera  described  agree  with  the  plant  studied,  and  in  that 
case  the  student  must  either  consult  a  larger  flora  or  rest 
satisfied  with  having  determined  the  family  to  which  his 

3 


4  FOUNDATIONS   OF   BOTANY 

specimen  belongs.1  The  identification  of  the  species,  after 
the  genus  has  been  reached,  presents  no  difficulty  in  a  little 
flora  like  the  present  one. 

The  author  does  not  believe  in  spending  much  of  the  time 
of  a  class  upon  identifying  species,  but  would  rather  recom- 
mend comparative  studies  of  as  many  plants  of  a  group  as 
are  accessible,  and  making  these  studies  thorough  enough  to 
bring  out  fully  the  idea  of  the  family,  the  genus,  and  the 
species.2  The  descriptions  in  this  flora  may  be  used  as  a 
check  on  the  cruder  ones  which  the  pupil  is  first  to  frame  for 
himself. 

1  It  will  greatly  simplify  matters  if  the  teacher  selects  for  examination  only  such 
species  as  are  here  described. 

2  The  teacher  will  find  abundant  suggestions  for  such  a  course  in  Spalding's 
Introduction  to  Botany,  pp.  152-260. 


KEY  TO   THE  FAMILIES   OF  FLOWEKING  PLANTS 
DESCRIBED   IN   THIS   FLOEA 


CLASS  I 

GYMNOSPERMS.    Ovules  not  enclosed  in  an  ovary. 

Trees  or  shrubs.  Leaves  tisually  evergreen  and  needle-shaped,  awl-shaped,  or 
scale-like.  Flowers  monoecious  or  dioecious.  Fruit  a  scaly  cone,  or  sometimes 
appearing  berry-like.  1.  pine  Family,  page  13 

CLASS  II 

ANGIOSPERMS.    Ovules  enclosed  in  an  ovary. 

SUBCLASS    I.  —MONOCOTYLEDONS.    Flowers  usually  with  their  parts 
in  threes,  never  in  fives.    Leaves  usually  parallel-veined.    Cotyledon  1. 

Flowers  enclosed  by  chaffy  bracts.                           FAMILY                     PAGE 
Flowers  2-bracted.    Leaves  2-ranked.    Stem  cylin- 
drical      4.  Grass 23 

Flowers   1-bracted.    Leaves  3-ranked.    Stem  trian- 
gular      5.  Sedge 23 

Flowers  on  a  spadix. 

Spadix  slender,  hairy,  and  bristly 2.   Cat-tail 20 

Spadix  fleshy     ..." 6.  Arum 23 

Flowers  not  on  a  spadix. 
Carpels  usually  numerous  and  nearly  or  entirely 

separate 3.  Water-plantain    .  21 

Carpels  united. 
Perianth  free  or  adnate  only  to  the  base  of  the  ovary. 

Perianth  regular,  its  parts  similar,  green,  or  chaffy     9.   Kush 29 

Perianth  of  2  sets,  one  sepal-like,  the  other  petal- 
like. 

Style  and  stigma  1.    Petals  3  or  2,  soon  disap- 
pearing     7.  Spiderwort    ...  26 

5 


b  FOUNDATIONS   OF   BOTANY 

Styles  or  stigmas  3,  separate.    Petals  3,  lasting  FAMILY  PAGE 
several  days.    Leaves  netted-veined     ....     IQ.   (Trillium)  Lily  .     29 
Style  1,  stigma  3-lobed,  or  6-toothed. 
Corolla  irregular.    Aquatic  herbs  with  par- 
allel-veined leaves 8.   Pickerel-weed  .     28 

Perianth  regular,  its  divisions  all  alike,  or  nearly 

so,  petal-like 10.   Lily 29 

Perianth  adnate  to  the  ovary. 

Anthers  6 11.  Amaryllis.    .    .     42 

Anthers  3 12.    Iris 45 

Anthers  lor  2 13>   Orchis     ....      4(5 

SUBCLASS   II.  —  DICOTYLEDONS.     Flowers  usually  with  their  parts  in 
fives  or  fours.    Leaves  netted-veined.    Cotyledons  2. 

I.    ApetalOUS  Division.    Flowers  without  a  corolla  or  without  either  calyx  or 
corolla.1 

A. 

Flowers  monoscious  or  dioecious,  one  or  both  sorts  in 

catkins. 

Staminate  flowers  in  catkins,  the  pistillate  ones  soli- 
tary or  clustered. 

Leaves  pinnately  compound ig.    "Walnut  49 

Leaves  simple 18>   Beech      ....      55 

Both  kinds  of  flowers  in  catkins. 
Leaves  alternate. 
Ovaries  in  fruit  becoming  fleshy  and  combining 

into  an  aggregate  fruit 20.   Mulberry   ...     61 

Fruit  1-seeded,  a  stone-fruit  or  minute  nut.  Aro- 
matic shrubs    15.  Bayberry  ...     49 

Fruit  a  capsule,  seeds  with  silky  hairs     ....      14.    "VVillow   .  47 

Fruit  a  minute  nut  or  akene.  Mostly  large  shrubs 

or  trees,  not  very  aromatic 17.   Birch 51 

Leaves  opposite,  small  parasitic  shrubs      ....     22.   Mistletoe    .  63 


B. 

Flowers  not  in  catkins,  both  calyx  and  corolla  wan  ting     44.    Sycamore.    .    .    105 

1  When  only  one  floral  envelope  is  present,  this  is  said  to  be  the  calyx  and  the 
corolla  is  considered  to  be  missing. 


KEY 


PAGE 


Flowers  not  in  catkins  ;  calyx  present,  sometimes  petal-like. 
Trees  or  shrubs. 

Flowers  not  hypogynous  ;  plants  not  climbing     .     .  73.   Dogwood      .    .    .    162 
Flowers  not  hypogynous  ;  climbing  plants    ....  24.    Dutchman's  Pipe     64 

Flowers  hypogynous. 
Style  single,  not  cleft,  fruit  a  key.    (Fraxinus)     .  78.    Olive     .....    175 

Style  single,  not  cleft,  fruit  a  stone-fruit  ....  37.   Laurel  .....      88 

Styles  2  or  2-cleft,  fruit  1-celled     .......   19.   Elm  ......      59 

Styles  2  or  2-cleft,  fruit  2-celled     .......   58.    Maple    .....    140 

Styles  3,  each  2-cleft.    Ovary  3-celled    .....  53.   Spurge      .    .    .    .135 

Herbs. 
Flowers  not  hypogynous  ;  ovary  6-celled  .....  24.  Dutchman's  Pipe     64 

Flowers  not  hypogynous  ;  ovary  1-celled  ;  flowers  in 
umbel-like  clusters     ......   |  .....  23.   Sandal  wood    .    .     64 

Flowers  hypogynous  ;  ovary  1-celled. 
Stamens  many  .....  -.    .    .......  32.   Buttercup    ...      77 

Stamens  few. 
Stipules  sheathing  the  joints  ........  25.   Buckwheat  ...     66 

Stipules  wanting. 
Rather  fleshy  herbs  ...........   26.    Goosefoot     ...      68 

Not  fleshy. 

Ovules  on  a  free  central  placenta  ;  delicate, 
soft-leaved  herbs.    (Stellaria)  .....  30.   Pink      .....      71 

Ovule  single.  Tough,  with  awl-shaped  leaves. 
(Scleranthus)     ...........  30.   Pink     .....     71 

Ovary  several-celled. 
Small  prostrate  herb  ;  leaves  spatulate,  whorled  .  28.    Ice-plant  ....      69 

Stipules  present,  not  sheathing. 
Style  single  ..............  21.  Nettle  .....     62 

s*yles  2    ...............  20.  Mulberry     ...     61 

Flowers  hypogynous,  ovary  3-celled      ......   53^    Spurge  .         .135 

Flowers  hypogynous,  ovary  5-10-celled  ;  fruit  a  berry  27.   Pokeweed    ...      69 

II.   PolypetalOUS  Division.   Calyx  and  corolla  both  present,  the  petals  not  united. 

A. 

Stamens  more  than  10. 

Trees,  shrubs,  or  woody  vines.    Leaves  alternate. 
Ovary  1,  simple. 
Fruit  a  stone-fruit    ...........  45.    Rose  m    195 


8  FOUNDATIONS   OF   BOTANY 

Ovary  1,  compound ;  fruit  dry.  FAMILY  PAGE 

Ovary  5-celled,  1-2-seeded  at  maturity  ....     63.   Linden    ....   146 

Ovary  3-celled,  many-seeded 68.   Begonia      .    .    .152 

Ovary  1, compound;  fruit  fleshy 45.   Rose 105 

Ovaries  numerous. 
Leaves  with,  stipules. 
Stamens  inserted  on  the  receptacle  ....     34.   Magnolia    ...      85 

Stamens  inserted  on  the  calyx 45.   Rose 105 

Leaves  not  with  stipules. 

Small  trees 36.   Pawpaw     ...     88 

Leaves  opposite  ;  fruit  dry. 

Ovary  single,  3-5-celled 43.   Saxifrage   ...    101 

Ovaries  several,  enclosed  by  the  calyx  tube    .    .     35.   Calycanthus  .    .     87 
Herbs. 

Ovary  single,  simple ;  fruit  a  berry 33.  Barberry    ...     84 

Ovaries  several,  simple. 
Stamens  inserted  on  the  receptacle     .....     32.   Buttercup  ...      77 

Stamens  inserted  on  the  calyx    .....'..     45.  Rose 105 

Ovary  compound. 

Aquatic  herbs,  leaves  flat 31.   Water-lily      .    .     75 

Marsh  herbs,  leaves  tubular 42.   Pitcher-plant    .   101 

Terrestrial  herbs. 
Ovary  1-celled. 

Placentae  central,  juice  watery     .....     29.   Purslane    ...     70 
Placentae  parietal,  juice  milky  or  colored     .     38.   Poppy     ....      89 

Placentae  2,  parietal .     40.   Caper      ....     99 

Placentae  3  or  more,  parietal. 

Leaves  alternate 41.   Mignonette    .    .   100 

Leaves  opposite 65.   St.  Johnswort  .   148 

Leaves  apparently  wanting,  stems  fleshy  .     69.    Cactus     .    .    .    .154 
Ovary  several-celled,  stamens  monadelphous  .     64.  Mallow  ....   147 
Ovary  3-celled,  stamens  not  much  if  at  all 
monadelphous,  stems  fleshy,  juice  watery 
and  acid 68.  Begonia ....  152 

B. 

Stamens  not  more  than  10. 
Trees,  shrubs,  or  woody  vines. 
Fruit  a  stone-fruit. 
Stamens  2,  rarely  3-4 78.   Olive 175 


KEY 


Stamens  as  many  as  the  petals.  FAMILY  PAGE 

Flowers  perfect. 

Stamens  4,  alternate  with  the  petals     ...     73.   Dogwood    .    .    .    162 
Stamens  5,  alternate  with  the  petals     .    .    .     54.   Sumac     ....    137 

Stamens  4-5,  opposite  the  petals 61.   Buckthorn     .    .   143 

Fruit  a  berry. 

Stamens  alternate  with  the  petals. 

Inserted  on  the  calyx,  leaves  simple    ....     43.    Saxifrage  .    .    .    101 
Inserted  on  a  disk  surrounding  the   ovary, 

leaves  compound 71.   Ginseng      .    .    .   157 

Stamens  opposite  the  petals    ........     62.   Grape  or  Vine  .   145 

Fruit  a  2-seeded  capsule  or  a  key. 

Leaves  compound 51.   Rue 133 

Fruit  a  3-5-celled  capsule,  flowers  small,  greenish, 

or  brown-purple,  leaves  simple 56.    Staff  Tree  .    .    .    139 

Fruit  5-lobed,  the  5  carpels  separating  when  ripe, 
flowers  rather  large,  white,  or  of  showy  colors, 

leaves  simple 47.   Geranium  .    .    .   129 

Fruit  a  1-3-celled  capsule,  leaves  compound,  flowers 

irregular 59.  Buckeye    .    .    .  142 

Fruit  a  3-celled  bladdery  capsule,  leaves  compound, 

flowers  regular 57.  'Bladder  Nut .    .   140 

Fruit  a  legume 46.   Pea  or  Pulse      .   117 

Herbs. 

Ovary  single,  1-celled,  simple  or  compound. 
Corolla  regular,  or  nearly  so. 
Sepals  and  petals  4-5  ;  stamens  5, 10,  or  12,  dis- 
tinct. 
Leaves  alternate. 

Stigma  single 46.   Pea  or  Pulse .    .   117 

Stigmas  4 43.  Saxifrage  ...  101 

Leaves  opposite,  punctate,  flowers  yellow    .    .     65.   St.  Johnswort    .   148 

Leaves  opposite,  flowers  white  or  red  .    .    .    .     39.   Pink  71 

Sepals  and  petals  4-5 ;  stamens  5,  united    ...     67.   Passion    Flower  151 

Sepals  2,  petals  4-5 29.  Purslane     ...     70 

Sepals  6,  stamens  hypogynous,  opposite  the  petals     33.  Barberry    ...     84 
Corolla  irregular. 

Fruit  a  legume 46.  Pea  or  Pulse .    .  117 

Fruit  a  capsule. 

Stamens  5 •  .    .    .     66.  Violet     ....   149 

Stamens  6,  in  2  sets 38.   Poppy     ....      89 


10  FOUNDATIONS   OF   BOTANY 

Ovary  single,  2-5-celled,  fruit  dry.  FAMILY  PAGE 

Ovary  2-celled. 

Flowers  in  umbels,  stamens  5 72.    Parsley      ....    158 

Flowers  not  in  umbels,  petals  4  or  0,  stamens  6  .  39.    Mustard   ....      93 
Flowers  not  in  umbels,  petals  3,  stamens  6  or  8  .  52.   Polygala  ....    134 

Ovary  a  4-celled  capsule 70.   Evening  Primrose  156 

Ovary  of  3  nearly  distinct  lobes,  which  become 

thick  and  fleshy  in  fruit 49.  Indian  Cress  .    .  132 

Ovary  a  5-celled  capsule. 
Leaves  simple. 

Parasitic  white  or  yellowish  herbs,  or  ever- 
green herbs,  not  parasitic,  capsule  many- 
seeded  74.  Pyrola 164 

Terrestrial,  not  much  if  at  all  fleshy,  capsule 

5-10-seeded 47.  Geranium    ...  129 

Terrestrial,  stem  fleshy  and  translucent,  cap- 
sule elastic,  several-seeded 60.  Balsam  ....  143 

Leaves  of  3  leaflets 48.   Wood-sorrel    .    .   131 

Ovary  of  5  principal  cells,  each  more  or  less  divided 
by  a  partition  into  2  cells ;  seeds  flattish,  with  a 

mucilaginous  coating 50.   Flax 132 

Ovary  single,  2-5-celled  ;  fruit  a  berry 71.    Ginseng    ....    157 

Ovaries  2,  seeds  hairy-tufted 81.    Milkweed     .    .    .    180 

III.    GamOpetalOUS  Division.    Calyx  and  corolla  both  present,  the  petals  more 
or  less  united. 

Trees,  shrubs,  or  woody  vines. 
Leaves  alternate. 
Fruit  splitting  open. 

Fruit  a  legume 46.  Pea  or  Pulse    .    .   117 

Fruit  a  5-celled  capsule 75.   Heath 166 

Fruit  not  splitting  open,  a  stone-fruit     .     .     .    .55.    Holly 138 

Fruit  a  berry. 

Ovary  not  adnate  to  the  calyx  ;  seeds  few,  large  77.   Ebony 174 

Ovary  not  adnate  to  the  calyx ;  seeds  many, 

small 88.  Nightshade ...  198 

Ovary  adnate  to  the  calyx 75.    Heath 166 

Leaves  opposite. 

Fruit  a  2-celled,  2-seeded  capsule 95.   Madder    ....  212 

Fruit  a  2-celled,  many-seeded  capsule. 
Seeds  winged 90.  Bignonia .    ...  206 


KEY  11 

• 

FAMILY  PAGE 

Seeds  not  winged ;  shrubs 96.   Honeysuckle     .  215 

Fruit  a  5-celled  capsule 75.   Heath 166 

Fruit  a  stone-fruit  or  berry. 

Fruit  1-2-seeded  ;  stamens  2 78.   Olive 175 

Fruit  1^4-seeded ;  stamens  4 86.   Verbena     .    .     .    192 

Fruit  1-5-seeded ;  stamens  5 96.   Honeysuckle      .   215 

Herbs. 

Ovary  not  adnate  to  the  calyx,  flowers  regular. 
Ovary  separating  into  2  distinct  follicles. 

Style  single,  stamens  distinct .     80.   Dogbane    .    .    .   178 

Styles  2,  stamens  united 81.   Milkweed  .    .    .   180 

Ovary  1-celled. 

Fruit  a  legume 46.   Pea  or  Pulse      .   117 

Fruit  a  capsule. 
Leaves  alternate. 

Stamens  opposite  the  lobes  of  the  corolla     .     76.   Primrose    .    .    .171 
Stamens    alternate  with  the  lobes  of   the 

corolla 84.   Waterleaf  ...   187 

Leaves  opposite 79.  Gentian ....  177 

Leaves  all  reduced  to  mere  scales,  plants  never 

green,  root-parasites 91.  Broom-rape  .    .   208 

Ovary  2-several-celled. 

Stamens  2  or  4 94.   Plantain     ...  211 

Stamens  5,  cells  of  the  ovary  1-2-seeded. 

Fruit  separating  into  4  nutlets 85.    Borage    .     .     .     .188 

Fruit  a  capsule 82.   Morning-glory  .   183 

Stamens  5,  cells  of  the  ovary  several-seeded. 

Stigma  l 88.  Nightshade    .    .  198 

Stigmas  3 83.  Phlox      ....   185 

Ovary  not  adnate  to  the  calyx,  flowers  irregular. 
Ovary  1-celled. 

Fruit  a  legume 46.   Pea  or  Pulse      .   117 

Fruit  a  capsule 92.   Bladderwort .    .  209 

Ovary  2-4-celled. 

Cells  each  1-seeded. 

Ovary  deeply  4-lobed 87.   Mint 193 

Ovary  not  deeply  lobed. 

Stamens  2  or  4 86.   Verbena     .    .    .   192 

Stamens  8 52.  Polygala    .    .    .   134 

Cells  each  2-several-seeded. 


12  FOUNDATIONS   OF   BOTANY 

FAMILY  PAGE 

Corolla  lobes  imbricated  in  the  bud  ....     89.  Figwort  ....   201 
Corolla  lobes  convolute  in  the  bud   ....     93.  Acanthus  .    .    .   210 
Ovary  adnate  to  the  calyx  tube. 

Flowers  in  an  involucrate  head 100.    Composite      .    .   224 

Flowers  not  in  heads. 
Stamens  3. 

Leaves  opposite 97.  Valerian     ...  220 

Leaves  alternate 98.   Gourd     ....  221 

Stamens  4-5. 

Leaves  alternate 99.  Campanula     .    .  223 

Leaves  opposite  or  whorled 95.   Madder  ....   212 


CLASS   L  —  GYMNOSPERMS. 

Plants  destitute  of  a  closed  ovary,  style,  or  stigma.  Ovules 
generally  borne  naked  on  a  carpellary  scale,  which  forms  part 
of  a  cone.  Cotyledons  often  several  (Fig.  1). 

1.    CONIFERJE.     PINE  FAMILY. 

Trees  or  shrubs  with  wood  of  peculiar  structure  (Part  I, 
Ch.  VI),  destitute  of  ducts,  with  resinous  and  aromatic  juice. 
Leaves  generally  evergreen,  and  needle-shaped  or  awl-shaped. 
Flowers  destitute  of  floral  envelopes,  monoecious  or  dioecious, 
the  staminate  ones  consisting  of  catkin-like  spikes  of  stamens 
and  the  pistillate  ones  consisting  of  ovule-bearing  scales, 
arranged  in  spikes,  which  ripen  into  cones. 


Each  scale  of  the  cone  borne  in  the  axil  of  a  bract.      Seeds  2,  with 
wings. 

Leaves  evergreen,  in  bundles  of  2-5.  Finns,  I. 

Leaves  evergreen,  solitary,  sessile,  keeled  on  both  surfaces. 

Picea,  II. 

Leaves  evergreen,  solitary,  petioled,  flat.  Tsuga,  III. 

Leaves  solitary,  evergreen,  flat  above,  keeled  below.     Abies,  IV. 
Leaves  clustered,  deciduous,  flat.  Larix,  V. 

B. 

Scales  of  the  cone  without  bracts,  cone  becoming  globular  and  woody. 
Leaves  linear. 

Leaves  alternate,  deciduous.  Taxodium,  VI. 

13 


14  FOUNDATIONS   OF   BOTANY 


Scales   of  the   cone  few,   without  bracts.     Leaves  evergreen,   generally 
scale-like  or  awl-shaped. 

Cones  dry  and  thin-scaled.  Thuya,  VII. 

Cones  berry-like.  Juniperus,  VIII. 

I.     PINUS,  Tourn. 

Sterile  flowers  somewhat  resembling  inconspicuous  catkins, 
borne  at  the  base  of  the  young  shoot  of  the  season,  each 
flower  consisting  of  pollen-scales  in  spiral  groups  (Fig.  1,  2). 
Fertile  flower-spikes  which  consist  of  spirally  arranged  carpel- 
scales,  each  scale  springing  from  the  axil  of  a  bract  and  bear- 
ing at  its  own  base  two  ovules  (Fig.  1,  3).  Fruit  a  cone, 
formed  of  the  thickened  carpellary  scales,  ripening  the  second 
autumn  after  the  flower  opens.  Primary  leaves,  thin  and 
chaffy  bud-scales,  from  the  axils  of  which  spring  the  bundles 
of  2-5  nearly  persistent,  needle-like,  evergreen  leaves,  from 
1-15  in.  long  (Fig.  1). 

1.  P.  Strobus,  L.     WHITE  PINE.     A  tall  tree,  75-160  ft.  high, 
much  branched  and  spreading  when  growing  in  open  ground,  but 
often  with  few  or  no  living  branches  below  the  height  of  100  ft. 
when  growing  in  dense  forests.     Leaves  clustered  in  fives,  slender, 
3-4  in.  long,  smooth,  and  pale,  or  with  a  whitish  bloom.     Cones 
5-6  in.  long,  not  stout.     The  wood  is  soft,  durable,  does  not  readily 
warp,  and  is  therefore  very  valuable  for  lumber.     In  light  soil,  com- 
monest N. 

2.  P.  Taeda,  L.      LOBLOLLY  PINE,   OLDFIELD  PINE.      A  large 
tree ;  bark  very  thick  and  deeply  furrowed,  becoming  flaky  with  age, 
twigs  scaly.     Leaves  in  threes,  6-10  in.  long,  slender,  very  flexible  ; 
sheaths  §-1  in.  long.     Cones  solitary,  oblong-conical,  3-5  in.  long ; 
scales  thickened  at  the  apex,  the  transverse  ridge  very  prominent 
and  armed  with  a  short,  stout,  straight,  or  recurved  spine.    Common 
and  often  springing  up  in  old  fields  ;  trunk  containing  a  large  pro- 
portion of  sap  wood ;  timber  of  little  value  for  outside  work.*1 

3.  P.    rigida,    Mill.      NORTHERN    PITCH   PINE.      A   stout   tree, 
30-80  ft.  high,  with  rough  scaly  bark.     Leaves  in  threes,  3-5  in. 
long,  stiff  and  flattened.     Cones  ovoid-conical,  2-3  in.  long,  their 

1  Descriptions  followed  by  an  asterisk  are  taken  (more  or  less  simplified)  from 
Professor  Tracy's  flora  in  the  Southern  States  Edition. 


GYMNOSPERMS 


15 


scales  tipped  with  a  short,  abruptly  curved  spine.  Wood  hard, 
coarse  and  resinous,  mainly  used  for  fuel.  Poor,  sandy  soil, 
especially  eastward. 


FIG.  1.  —  Scotch  Pine  (P.  sylvestris). 

1,  a  twig  showing  :  a,  staminate  catkins  ;  b,  pistillate  catkins  ;  c,  a  cone  ;  d,  needles. 
2,  an  anther,  a,  side  view  ;  b,  outer  surface.  3,  a  carpel-scale,  a,  inner  surface  ; 
b,  outer  surface.  4,  a  cone-scale,  a  seed-wing,  and  a  seed.  5,  section  of  a  seed, 
showing  the  embryo.  (1)  is  natural  size  ;  the  other  parts  of  the  figure  are  magni- 
fied by  the  amount  indicated  by  comparison  with  the  vertical  line  alongside  each. 

4.  P.  inops,  Ait.  SCRUB  PINE.  A  small  tree,  usually  20-30  ft. 
high,  but  sometimes  much  taller ;  bark  of  the  trunk  rough,  nearly 
black;  twigs  smooth  and  with  a  bloom.  Leaves  in  twos,  1-2  in. 


16  FOUNDATIONS   OF  BOTANY 

long,  rigid,  sheaths  very  short.  Staminate  catkins  dull  yellowish- 
purple,  1  in.  long.  Cones  solitary,  short-peduncled,  often  reflexed, 
ellipsoid-conic,  about  2  in.  long  ;  scales  thickened  at  the  apex  and 
armed  with  a  slender,  straight,  or  recurved  prickle.  On  dry,  sandy 
soil ;  wood  light,  soft,  weak,  and  of  little  value.* 

5.  P.  sylvestris,  L.    SCOTCH  PINE  (wrongly  called  Scotch  Fir).    A 
medium-sized  tree,  with  the  older  bark  reddish  and  scaly.     Leaves  in 
twos,  1|— 2^  in.  long.     Cones  rather  small  and  tapering  (Fig.  1,  I  c). 
Cultivated  from  Europe. 

6.  P.  resinosa,  Ait.     RED  PINE,  NORWAY  PINE.     A  tall,  rather 
slender   tree,    with    bark    reddish-brown    and    moderately   smooth. 
Leaves  in  twos,  slender,  and  5-6  in.  long.     Cones  borne  at  the  ends 
of  the  branches,  smooth,  about  2  in.  long.     A  valuable  timber  tree, 
which  often  grows  in  small,  scattered  clumps ;  wood  firm,  pale  red, 
and  not  very  resinous ;  used  in  house  and  bridge  building,  and  for 
masts  and  spars. 

7.  P.  palustris,  Mill.     LONG-LEAVED  PINE.     A  large  tree ;   bark 
thin-scaled,  wood  very  resinous,  old  trees  with  only  a  few  spreading 
branches  near  the  top.     Leaves  in  threes,  10—15  in.  long.     Sheaths 
1-1£  in.  long,  crowded  near  the  ends  of  very  scaly  twigs.    Staminate 
catkins  2-3  in.  long,  bright  purple,  conspicuous.     Cones  terminal, 
ellipsoid -conical,  6-10  in.  long,  diameter  2-3  in.  before  opening,  4-6 
in.  when  fully  opened ;  scales  much  thickened  at  the  apex  and  armed 
with  a  short  recurved  spine  at  the  end.     The  most  common  tree  in 
the  pine  barrens ;  wood  hard,  strong,  and  durable,  especially  valua- 
ble for  floors  and  inside  work.* 


II.     PICEA,  Link. 

Sterile  flowers  generally  axillary  (sometimes  terminal),  borne 
on  the  twigs  of  the  preceding  year.  Fertile  flowers  terminal. 
Fruit  a  nodding,  thin-scaled  cone,  ripening  in  the  first  autumn. 
Leaves  evergreen,  needle-shaped,  four-angled,  scattered  or 
spirally  arranged. 

1.  P.  nigra,  Link.     BLACK  SPRUCE.     A  small  tree,  usually  only 
20  or  30  ft.  high,  often  less.     Leaves  strongly  4-angled,  bluish-green, 
and  glaucous,  ^-f  in.  long.     Cones  ovoid,  pointed,  £-l£  in.,  usually 
about  1  in.  long,  persisting  sometimes  for  20-30  years.     Wood  of 
little  value  except  for  paper-pulp.     The  tree  is  especially  abundant 
northward,  and  is  of  common  occurrence  in  peat-bogs. 

2.  P.  rubra,  Dietrich.     RED  SPRUCE.     A  large  tree,  70-80  or  even 
100  or  more  feet  high,  of  strict  conical  habit.     Leaves  dark  green 
or  yellowish  and  glossy,  |— |  long.    Cones  ovoid-oblong,  acute,  usually 
l£-2  in.  long,  mostly  falling  the  first  year.     This  is  the  principal 


GYMNOSPERMS  17 

timber-spruce  of  the  northeastern  United  States,  and  furnishes  much 
rather  tough  lumber  for  use  in  floor-joists,  scantling,  and  similar 
purposes. 

3.  P.  alba,  Link.    WHITE  SPRUCE,  SKUNK  SPRUCE,  CAT  SPRUCE. 
A  tall,  rather  conical  tree,  60-70  ft.  high.     Leaves  pale  and  with  a 
bloom  sometimes  f  in.  long.     Cones  cylindrical,  with  rounded  ends, 
about  2    in.  long,  falling  inside  of  one   year.     A  handsome  tree, 
valuable  for  timber,  ranging  far  northward. 

4.  P.  excelsa,  Link.     NORWAY  SPRUCE.     A  large  tree.     Leaves 
dark  green,   f-1   in.  long.     Cones  5-7  in.   long.      Cultivated  from 
Europe. 

III.     TSUGA,  Carriere. 

Sterile  flowers,  clusters  of  stamens  springing  from  the  axils 
of  leaves  of  the  preceding  year.  Cones  terminal,  on  twigs  of 
the  preceding  year,  drooping,  thin-scaled,  ripening  the  first 
year.  Leaves  minutely  petioled,  short,  flat,  white  beneath, 
2-ranked. 

1.  T.  canadensis,  Carriere.  HEMLOCK.  A  large  tree,  in  age 
branchless  below  when  growing  in  dense  woods.  When  young  the 
spray  is  very  graceful  and  abundant.  Leaves  short-linear.  Cones 
^  in.  or  less  in  length.  The  wrood  is  coarse  and  splintery,  but  useful 
for  fences  and  other  rough  work.  The  thick  reddish  bark  is  of 
great  value  for  tanning. 

IV.  ABIES,  Link. 

Sterile  flowers  from  axils  of  leaves  of  the  preceding  year. 
Cones  erect,  on  the  sides  of  the  branches,  with  deciduous 
scales,  ripening  the  first  year.  Leaves  scattered,  but  on  hori- 
zontal branches  appearing  2-ranked,  flat  above,  silvery,  and 
with  a  prominent  midrib  below. 

1.  A.  balsamea,  Miller.  BALSAM  FIR.  A  slender  tree,  50-60 
ft.,  occasionally  80  ft.,  high,  with  dense  foliage.  Leaves  narrowly 
linear,  less  than  1  in.  long.  Cones  violet-colored  until  old,  cylindri- 
cal, 2-4  in.  long.  The  bark  contains  many  large  blisters,  filled  with 
the  well-known  Canada  balsam.  The  wood  is  brittle,  and  of  little 
value. 

V.  LARIX,   Tourm. 

Flower-spikes  short,  opening  in  early  spring,  before  the 
leaves  ;  the  fertile  ones,  while  still  young,  of  a  beautiful  crim- 


18  FOUNDATIONS   OF   BOTANY 

son  color.  Fruit  a  small  cone,  with  thin  scales.  Leaves  none 
of  them  scaly,  but  all  needle-shaped,  soft,  deciduous,  very 
numerous,  in  little  brush-like  bundles. 

1.  L.  americana,  Michx.    AMERICAN  LARCH,  TAMARACK,  HACK- 
MATACK (wrongly,  but  quite  generally,  called  Cypress  and  Juniper). 
A  tall,  slender  tree,  30-100  ft.  high.     Leaves  slender  and  less  than 
1  in.  long,  very  pale  bluish-green.     Cones  £-f  in.  long,  few-scaled. 
Wood  hard,  tough,  and  heavy,  of  considerable  use  for  ship-building. 

2.  L.  europaea,  DC.      EUROPEAN  LARCH.     Leaves  bright   green 
and  longer ;  cones  longer  than  in  the  preceding  species  and  many- 
scaled.     Cultivated  from  Europe. 

VI.     TAXODIUM,  Richard. 

Trees ;  leaves  spreading  so  as  to  appear  2-ranked,  decidu- 
ous ;  flowers  monoecious,  appearing  before  the  leaves ;  stain i- 
nate  ones  numerous,  globose  ;  forming  long,  terminal,  drooping, 
panicled  spikes ;  anthers  2-5-celled ;  pistillate  flowers  single 
or  in  pairs,  bractless,  the  peltate  scales  2-ovuled ;  cone  globose ; 
the  very  thick  woody  scales  angular,  separating  at  maturity ; 
seeds  3-angled,  pyramidal.* 

1.  T.  distichum,  Richard.  BALD  CYPRESS.  A  very  large  tree; 
bark  dark  brown,  rough,  fibrous  ;  many  of  the  twigs  deciduous  witli 
the  leaves.  Leaves  alternate,  opposite,  or  whorled,  2-ranked,  flat, 
linear,  £-f  in.  long.  Cones  terminal,  globose,  about  1  in.  in  diameter  ; 
ends  of  the  scales  much  thickened,  wrinkled,  and  with  a  distinct 
triangular  marking.  Common  in  swamps  and  on  the  borders  of 
streams;  wood  reddish,  soft,  light;  specially  valuable  for  shingles 
and  fence  posts,  and  for  boat-building.* 

VII.     THUYA,  Tourn. 

Flowers  small,  terminal,  monoecious,  on  different  branches. 
Stamens  each  consisting  of  a  scale-like  portion  bearing  4  anther- 
cells.  Pistillate  flowers  consisting  of  a  few  overlapping  scales 
which  ripen  into  a  small,  loose  cone.  Leaves  evergreen,  oppo- 
site, and  closely  overlapping  on  the  stem,  of  two  kinds,  those 
on  the  more  rapidly  growing  twigs  awl-shaped,  the  others  mere 
scales. 

1.  T.  occidentalis,  L.  ARBOR  VIT^E,  CEDAR.  A  small  tree,  20-50 
ft.  high,  with  soft  fibrous  bark.  Leaves  mostly  awl-shaped  and  blunt. 


GYMNOSPERMS  19 

Cones  ellipsoidal,  their  scales  2-seeded.  Grows  on  rocky  ledges,  but 
reaches  its  greatest  size  in  cool  cedar  swamps.  Wood  soft,  yellowish, 
fragrant,  durable,  prized  for  shingles  and  fence  posts. 

VIII.     JUNIPERUS,  L. 

Flowers  very  small,  lateral,  dioecious,  or  sometimes  monoe- 
cious. Scales  of  the  staminate  flower  shield-shaped,  with  3-6 
anther-cells.  Fertile  flowers  with  3-6  fleshy  scales  which 
unite  into  a  berry-like,  1-3-seeded  fruit.  Leaves  awl-shaped 
or  scale-shaped. 

1.  J.   communis,    L.     JUNIPER.     A    low,    spreading   shrub    (one 
variety  prostrate  in  circular  masses).     Leaves  linear-awl-shaped,  with 
needle-like  points,  each  marked  with  a  distinct  stripe  of  bloom  along 
the  center  of  the  upper  surface,  borne  in  whorls  of  three.     Fruit  a 
dark  blue  aromatic  berry,  £  in.  or  more  in  diameter.     Grows  in  dry 
pastures  and  on  sterile  hillsides  N. 

2.  J.  virginiana,  L.     RED  CEDAR,  SAVIN.     Ranges  in  size   and 
shape  from  a  low,  rather  erect,  shrub  to  a  conical  tree  90  ft.  high. 
Leaves  of  two  kinds,  those  on  the  rapidly  growing  shoots  awl-shaped 
and  pointed,  those  on  the  shortest  twigs  scale-shaped,  obtuse,  or 
nearly  so,  and  closely  appressed  to  the  stem.     Fruit  small,  bluish, 
with  a  white  bloom.     Found  all  the  way  from  British  America  to 
Florida.     Wood  soft,  fragrant,  reddish,  exceedingly  durable  in  the 
ground,  valued  for  the  manufacture  of  moth-proof  chests  and  espe 
cially  for  lead-pencils. 


20  FOUNDATIONS  OF  BOTANY 


CLASS   II.  —  ANGIOSPERMS. 

Plants  with  a  closed  ovary,  in  which  the  seeds  are  matured. 
Cotyledons  1  or  2. 

SUBCLASS   I.  — MONOCOTYLEDOKOUS   PLANTS. 

Stems  with  the  fibro-vascular  bundles  scattered  among  the 
parenchyma  cells  ;  in  perennial  plants  no  annual  rings  of 
wood.  Leaves  usually  parallel-veined,  alternate,  nearly 
always  entire.  Parts  of  the  flower  generally  in  threes 
(never  in  fives).  Cotyledon  1. 

2.    TYPHACE^J.     CAT-TAIL  FAMILY. 

Perennial  marsh  or  aquatic  plants.  Eootstock  stout,  creep- 
ing; stem  simple,  cylindrical,  erect.  Leaves  simple,  strap- 
shaped,  sheathing  at  the  base,  nerved  and  striate.  Flowers 
monoecious,  in  a  single  terminal  spike,  staminate  part  of  the 
spike  uppermost,  each  part  subtended  by  spathe-like  deciduous 
bracts ;  perianth  of  fine  bristles  ;  staminate  flowers  sessile  ; 
stamens  2-7.  Filaments  connate,  subtended  by  minute  bracts ; 
pistillate  flowers  short-pediceled.  Ovary  1-2-celled  ;  styles 
1-2.  Fruit  small,  nut-like.* 

TYPHA,  Tourn. 
Characters  of  the  family. 

1.  T.  latifolia,  L.  CAT-TAIL.  Stem  erect,  jointed  below,  5-8  ft. 
high.  Leaves  nearly  as  long  as  the  stem,  about  1  in.  wide,  netted 
and  with  a  bloom.  Spike  cylindrical,  dark  brown  or  black ;  staminate 
portion  above  the  pistillate,  usually  without  any  interval  between 
them,  each  4-8  in.  long  and  about  1  in.  in  diameter.  Fruit  furrowed. 
Common  in  marshes  and  shallow  ponds.* 


MONOCOTYLEDONOUS   PLANTS  21 


3.   ALISMACE^.     WATER-PLANTAIN   FAMILY. 

Annual  or  perennial  marsh  herbs,  usually  with  creeping  run- 
ners or  rootstocks.  Stems  scape-like.  Leaves  long-petioled, 
sheathing  at  the  base  ;  petiole  rounded  ;  blade  nerved,  netted, 
or  sometimes  wanting.  Flowers  in  racemes  or  panicles,  per- 
fect, monoecious  or  dioecious  ;  pedicels  in  bracted  whorls. 
Sepals  3,  persistent,  petals  3  or  wanting.  Stamens  6  or  more. 
Ovaries  few  or  many,  1-celled,  1-seeded.  Style  short  or  none. 
Fruit  a  1-seeded  akene.* 

I.     ALISMA,   L. 

Annual  or  perennial  herbs.  Leaves  erect  or  floating,  blades 
prominently  ribbed  and  netted,  or  even  pinnately  veined. 
Scapes  erect,  becoming  longer  than  the  leaves,  cylindrical, 
spongy.  Flowers  perfect,  in  paniculate  3-bracted  umbels, 
small,  white  or  pink.  Stamens  6-9.  Ovaries  numerous  in 
one  or  more  whorls  on  a  flat  receptacle.  Fruit  1-seeded 
akenes  which  are  ribbed  on  the  back  and  sides.* 

1.  A.  Plantago,  L.  WATER  PLANTAIN.  Perennial;  root  fibrous. 
Leaves  ovate  or  somewhat  cordate,  5-7-nerved  when  erect,  floating 
leaves  narrower  and  sometimes  linear.  Scapes  usually  single  ;  pan- 
icle 1-2  ft.  long  ;  flowering  branches  whorled,  subtended  by  three 
narrow,  striate  bracts ;  pedicels  slender,  elongated.  Ovaries  15—20 
in  a  single  whorl ;  base  of  the  short  style  persistent,  forming  a  beak 
at  the  inner  angle  of  the  akene.  Akenes  obliquely  obovate,  2-3- 
keeled  on  the  back.  Common  in  ponds  and  muddy  places.* 

II.     SAGITTARIA. 

Perennial  ;  rootstocks  mostly  knobby  or  tuber-bearing. 
Scapes  erect  or  decumbent.  Leaves  long-petioled,  sheathing 
at  the  base,  the  blade  round  and  netted,  or  wanting.  Flowers 
monoecious  or  dioecious,  racemed  in  3-bracted  whorls  of  threes, 
the  upper  flowers  usually  staminate.  Sepals  3,  persistent. 
Petals  3,  withering-persistent  or  deciduous.  Stamens  few  or 
many.  Ovaries  in  globose  heads,  1-ovuled  ;  style  short,  per- 
sistent. Fruit  a  subglobose  head  of  flattened  akenes.* 


22 


FOUNDATIONS   OF   BOTANY 


1.  S.  variabilis,  var.  latifolia,  Willd.      BROAD-LEAVED   ARROW- 
HEAD.    Leaves   very  variable    in    size    and   shape,    from    broadly 
sagittate  to  linear ;  those  growing  on  the  drier  soil  being  usually  the 
broader ;  petioles  6-30  in.  long.     Scape  smooth  or  slightly  downy, 
6-36  in.   high;   bracts  acute.      Flowers  monoecious  or   sometimes 
dioecious,  white,  1  in.  or  more  in  width;  pedicels  of  the  staminate 
flowers  twice  the  length  of  those  of  the  fertile  flowers.     Filaments 
long,  smooth,  and  slender.     Akenes  with  beak   nearly  horizontal. 
Ditches  and  muddy  places.* 

2.  S.  graminea,  Michx.      GRASS-LEAVED   SAGITTARIA.     Leaves 
long-petioled,  lanceolate,  or  elliptical,  and  acute  at  each  end,  3-5- 
nerved,  or  often  linear,  the  earlier 

often  reduced  to  flattened  petioles. 
Scape  slender,  usually  longer  than 
the  leaves,  simple,  weak,  often  pros- 
trate in  fruit;  bracts  small,  ovate, 
connate  at  the  base.  Flowers  monoe- 
cious o»  dioecious,  on  long,  thread- 
like pedicels,  about  £  in.  wide. 
Stamens  10-20,  filaments  downy. 
Akenes  nearly  beakless.  In  ditches 
arid  shallow  pools.* 


FIG.  2.  — Diagram  of  Inflorescence 
of  a  Grass. 

,  sterile  glumes  ;  P15  a  flowering  glume  ; 
P2,  a  scaly  bract  (palea) ;  e,  transparent 
scales  (lodicules)  at  the  base  of  the 
flower  ;  B,  the  flower. 


FIG.  3.— Fescue-grass  (Festuca 
pratensis). 

A,  spikelet  (compare  Fig.  2) ;  B,  a 
flower,  the  lodicules  in  front  and 
the  palea  behind ;  C,  a  lodicule ; 
Z),  ovary. 


MONOCOTYLEDONOUS   PLANTS  28 


4.    GRAMINEJE.     GRASS  FAMILY. 

Mostly  herbs,  with  usually  hollow  stems,  closed  and  en- 
larged at  the  nodes.  Leaves  alternate,  in  two  ranks,  with 
sheathing  bases,  which  are  split  open  on  the  side  opposite  the 
blade.  Flowers  nearly  or  quite  destitute  of  floral  envelopes, 
solitary,  and  borne  in  the  axils  of  scaly  bracts  called  glumes, 
which  are  arranged  in  two  ranks  overlapping  each  other  on 
1-many-flowered  spikelets ;  these  are  variously  grouped  in 
spikes,  panicles,  and  so  on.  Fruit  a  grain.  (The  family  is 
too  difficult  for  the  beginner,  but  the  structure  and  group- 
ing of  the  flowers  may  be  gathered  from  a  careful  study  of 
Figs.  2,  3.) 


5.    CYPERACEJE.     SEDGE  FAMILY. 


Grass-like  or  rush-like  herbs,  with  solid,  usually  triangular, 
stems,  growing  in  tufts.  The  sheathing  base  of  the  generally 
3-ranked  leaves,  when  present,  is  not  slit  as  in  grasses.  The 
flowers  are  usually  somewhat  less  enclosed  by  bracts  than 
those  of  grasses  ;  the  perianth  is  absent  or  rudimentary ; 
stamens  generally  3  ;  style  2-cleft  or  3-cleft. 

The  general  appearance  of  a  common  sedge  may  be  learned 
from  Part  I,  Ch.  V,  and  the  flower-cluster  and  the  flower 
understood  from  an  inspection  of  Fig.  4. 

The  species  are  even  more  difficult  to  determine  than  those 
of  grasses. 

6.   ARACE-ffi.     ARUM  FAMILY. 

Perennial  herbs,  with  pungent  or  acrid  juice,  leaves  often 
netted-veined,  small  flowers  (perfect  or  imperfect)  clustered 
along  a  peculiar  fleshy  spike  called  a  spadix,  and  frequently 
more  or  less  covered  by  a  large,  hood-like  bract  called  a 
spathe.  Perianth,  when  present,  of  4-6  parts  ;  often  want- 
ing. Fruit  usually  a  berry. 


24 


FOUNDATIONS   OF   BOTANY 


FIG.  4.— Inflorescence,  Flower,  and  Seed,  of  a  Sedge. 
(Great  Bulrush,  Scirpus  lacustris.) 

A,  magnified  flower,  surrounded  by  a  perianth  of  hypogynous  bristles  ;  £,  the 
seed ;  C,  section  of  the  seed,  showing  the  small  embryo  enclosed  hi  the  base 
of  the  endosperm. 


I.     ARIS^EMA,  Martius. 

Perennial  herbs,  springing  from  a  corm  or  a  tuberous 
rootstock. 

Spathe  rolled  up  at  base.  Summit  of  spadix  naked,  the 
lower  part  flower-bearing ;  staminate  flowers  above,  pistil- 
late ones  below.  Stigma  flat ;  ovary  1-celled  ;  berry  1-few- 
seeded. 


MONOCOTYLEDONOTJS   PLANTS  25 

1.  A.   triphyllum,   Ton.     INDIAN    TURNIP,   JACK-IN-THE-PULPIT. 

Leaves  generally  2,  each  of  3  elliptical-ovate,  pointed  leaflets.  Spadix 
club-shaped,  bearing  usually  only  one  kind  of  fully  developed  flowers  ; 
that  is,  full-sized  pistillate  and  rudimentary  staminate  ones,  or  the 
reverse.  Spathe  much  longer  than  the  spadix,  and  covering  it  like 
a  hood.  Corm  turnip-like,  but  much  wrinkled,  very  starchy,  and 
filled  with  intensely  burning  juice. 

2.  A.  Dracontium,  Schott.    GREEN  DRAGON,  DRAGON  ROOT.    Leaf 
usually    single,    divided  into  7-11   rather  narrow-pointed  leaflets  ; 
spadix  tapering  to  a  long,  slender  point,  often  bearing  fully  devel- 
oped staminate  and  pistillate  flowers. 


H.     SYMPLOCARPUS,  Salisb. 

Kootstock  very  stout,  with  many  long,  cylindrical  roots. 
Leaves  clustered,  very  large,  and  entire.  Spathe  shell-shaped, 
very  thick.  Spadix  globular,  thickly  covered  with  perfect 
flowers.  Sepals  4.  Stamens  4.  Style  4-angled.  Fruit  glob- 
ular or  ellipsoidal,  with  the  seeds  slightly  buried  in  the 
enlarged  spadix. 

Coarse,  stemless  herbs,  with  a  powerful  scent  like  that  of 
the  skunk  and  of  onions. 

1.  S.  foetidus,  Salisb.  SKUNK  CABBAGE.  Leaves  many,  slightly 
petioled,  1-2  ft.  long,  appearing  after  the  flowers.  The  latter  are 
usually  seen  before  the  ground  is  wholly  free  from  frost,  often  earlier 
than  any  other  flower.  Bogs  and  wet  meadows,  very  common  N. 


HI.     ACORUS,  L. 

Rootstocks  horizontal,  long,  and  moderately  stout,  aromatic. 
Leaves  long,  upright,  sword-shaped.  Spathe  much  like  the 
leaves.  Spadix  projecting  from  the  edge  of  the  spathe,  con- 
sisting of  numerous  perfect  flowers.  Sepals  6.  Stamens  6. 
Ovary  2-3-celled,  with  numerous  ovules.  Fruit  1-few-seeded. 

1.  A.  Calamus,  L.  SWEET  FLAG.  Scape  with  a  long,  leaf-like 
prolongation  (spathe)  beyond  the  green,  very  closely  flowered,  spadix. 
Along  borders  of  brooks  and  swamps. 

The  rootstocks  furnish  the  well-known  calamus  or  "  sweet  flag- 
root  "  sold  everywhere  by  druggists. 


26 


FOUNDATIONS   OF   BOTANY 


7.    COMMELINACE^.     SpiDERWORT  FAMILY. 

Herbs,  with  slimy  or  mucilaginous  juice  ;  stems  somewhat 
succulent,  jointed,  leafy,  simple  or  branched.  Leaves  simple, 
succulent,  narrow,  entire,  sheathing  at  the  base,  sheaths  entire 


B 


FIG.  5.  —  Acorus  Calamus. 
A,  spadix  ;  B,  a  single  flower,  enlarged  ;  C,  diagram  of  flower,  enlarged. 

or  split.  Flowers  in  terminal  cymes  or  umbels,  perfect,  often 
irregular.  Sepals  3,  persistent,  foliaceous  or  colored.  Petals  3, 
soon  falling  or  liquefying  ;  stamens  6  or  fewer,  often  some  of 
them  abortive.  Ovary  2-3-celled  ;  style  single,  stigma  entire 
or  3-lobed,  fruit  a  2-3-celled,  2-3-valved  capsule,  seeds  soli- 
tary or  several  in  each  cell.* 


MONOCOTYLEDONOUS  PLANTS  27 


I.     COMMELINA,  Dill. 

Annual  or  perennial,  stem  branching,  erect  or  procumbent, 
smooth  or  downy.  Leaves  petioled  or  sessile,  entire,  the 
floral  ones  heart-shaped,  folded,  and  forming  a  spathe  enclos- 
ing the  base  of  the  cymes.  Flowers  irregular,  sepals  mostly 
colored,  1  of  them  smaller.  Petals  blue,  unequal,  2  of  them 
kidney-shaped  and  long-clawed,  the  other  smaller.  Stamens  6, 
only  3  of  them  fertile,  filaments  smooth.  Capsule  1-3-celled, 
seeds  1-2  in  each  cell.* 

1.  C.  virginica,  L.  VIRGINIA  DAYFLOWER.  Stem  erect,  downy, 
1-2  ft.  high.  Leaves  lanceolate  to  oblong-lanceolate,  taper-pointed, 
3-5  in.  long,  somewhat  rough  above,  sheaths  inflated,  hairy, 
the  opening  often  fringed.  Spathes  containing  a  slimy  secretion. 
Flowers  1  in.  wide,  the  odd  petal  lanceolate.  Capsule  3-seeded,  the 
dorsal  cell  not  splitting  open.  On  moist,  sandy  soil.* 


II.     TRADESCANTIA,  L. 

Perennial,  stem  simple  or  branched.     Leaves  very  narrow. 
Flowers  in  terminal   and  axillary  bracted   umbels,  regular, 

1  in.  broad.     Sepals  3,  herbaceous.     Petals  3,  soon  falling  or 
liquefying  to  jelly.     Stamens  6,  sometimes  3  shorter  than  the 
others,  filaments  bearded  or  smooth.     Ovary  3-celled,  with 

2  ovules  in  each  cell,  pedicels  recurved  in  fruit.      Capsule 
3-celled,  3-valved,  3-6-seeded.* 

1.  T.   virginica,   L.     SPIDERWORT.     Stem  erect,  stout,  smooth, 
or  with  long,  soft  hairs,  1-2  ft.  high.     Leaves  linear,  keeled,  often 
purple-veined,  long,  taper-pointed,  1  ft.  or  more  in  length.     Bracts 
similar  to  the  leaves,  umbels  sessile,  2-many-flowered,  flowers  in  2 
rows  in  the  bud.     Petals  blue  or  purple,  twice  as  long  as  the  sepals. 
Stamens  blue,  filaments  densely  bearded.     Capsule  ovoid  or  oblong. 
On  dry,  sandy  soil.* 

2.  T.  pilosa,  Lehm.     HAIRY  SPIDERWORT.     Stem  stout,  erect,  or 
zigzag,  branched,  with  long,  soft  hairs,  or  nearly  smooth,  1-2  ft. 
high.    Leaves  linear-oblong,  taper-pointed  at  the  apex,  narrowed  at 
the  base,  hairy  on  both  sides.    Umbels  axillary  and  terminal,  many- 
flowered.     Pedicels  and  sepals  with  soft,  glandular  hairs.     Flowers 
blue  or  purple,  |-1  in.  wide.     Seeds  pitted.     In  rich  soil,* 


28  FOUNDATIONS   OF   BOTANY 


HI.     ZEBRINA. 

Trailing  or  slightly  climbing  herbs.  Leaves  often  striped. 
Flowers  irregular,  usually  in  pairs.  Calyx  with  a  short  tube, 
regularly  or  irregularly  3-parted.  Corolla  nearly  regular, 
with  tube  longer  than  the  calyx.  Filaments  naked  or  bearded. 
Ovary  3-celled,  3-6-ovuled. 

1.  Z.  pendula,  Schnitzl.  WANDERING  JEW.  Stems  perennial, 
prostrate,  or  nearly  so,  branching  freely,  rooting  easily  at  the  nodes. 
Leaves  somewhat  succulent,  lance-ovate  or  oblong,  crimson  beneath, 
green  or  dark  purplish  above,  often  with  two  wide  silvery  stripes. 
Cultivated  from  Mexico. 


8.    PONTEDERIACE^).     PICKEREL-WEED  FAMILY. 

Perennial  marsh  or  aquatic  herbs,  stems  simple  or  branched, 
succulent.  Leaves  simple,  alternate.  Flowers  solitary  or 
spiked,  each  subtended  by  a  leaf-like  spathe,  perfect,  mostly 
irregular.  Perianth  corolla-like,  6-parted.  Stamens  3  or  6, 
unequal,  inserted  irregularly  in  the  tube  or  throat  of  the 
perianth.  Ovary  free,  style  single,  stigma  entire  or  toothed, 
ovary  1  or  3  celled.  Fruit  a  1-seeded  utricle.* 

PONTEDERIA,  L. 

Stem  erect,  from  a  thick,  creeping  rootstock,  bearing  a 
single  leaf  above  the  middle  and  several  sheathing,  bract-like 
leaves  at  its  base.  Eadical  leaves  numerous,  thick,  parallel- 
veined.  Petiole  long,  from  a  sheathing  base.  Flowers  in 
terminal  spikes.  Perianth  2-lipped,  lobes  of  the  upper  lip 
ovate,  of  the  lower  oblong,  spreading.  Stamens  6,  the  3 
upper  short  and  often  imperfect,  the  3  lower  protruding. 
Ovary  3-celled,  but  only  1  cell  ovule-bearing.  The  1-seeded 
utricle  enclosed  by  the  base  of  the  perianth.* 

1.  P.  cordata,  L.  PICKEREL-WEED.  Stem  stout,  erect,  2—4  ft.  high. 
Leaves  long,  from  heart-shaped  to  lanceolate  and  often  halberd- 
shaped,  apex  and  basal  lobes  obtuse,  finely  nerved.  Spike  dense, 


MONOCOTYLEDONOUS  PLANTS  29 

2-4  in.  long,  peduncles  enclosed  by  the  spathe.  Perianth  hairy, 
blue,  the  upper  lip  with  2  yellow  spots,  tube  6-ribbed,  curved,  rather 
longer  than  the  lobes.  Ovary  oblong.  In  ponds  and  slow  streams.* 


9.  JTJNCACE^.     RUSH  FAMILY. 

Grass-like  perennial  or  annual  herbs,  mostly  growing  on 
wet  soil.  Stems  mostly  erect  but  sometimes  creeping,  simple 
or  branched,  naked  or  leafy  and  jointed.  Leaves  cylindrical, 
sheathing  at  the  base,  very  slender  and  pointed  or  flattened 
and  grass-like.  Flowers  in  cymes  or  panicles,  which  may  be 
very  loose  and  spreading,  or  so  compact  as  to  form  a  head, 
sometimes  with  a  rigid  scape  prolonged  beyond  the  flower- 
cluster.  Flowers  usually  bracted,  perianth  of  6  nearly  equal 
scale-like  persistent  divisions.  Stamens  3  or  6,  inserted  on 
the  base  of  the  perianth.  Ovary  free,  1  or  3  celled,  many- 
ovuled.  Style  single,  stigmas  3,  usually  hairy.  Fruit  a  1  or 
3  celled,  3-many-seeded  capsule.  [Most  species  flower  late  in 
the  season,  and  their  identification  is  too  difficult  for  one 
without  considerable  experience.]  * 

10.  LILIACE^.     LILY  FAMILY. 

Mostly  herbs.  Flowers  regular  and  symmetrical.  Perianth 
free  from  the  ovary.  Stamens  nearly  always  6,  one  before 
each  division  of  the  perianth.  Ovary  usually  3-celled.  Fruit 
a  pod  or  berry,  few— many-seeded. 

Except  in  the  genus  Trillium  the  divisions  of  the  perianth 
are  colored  nearly  alike. 


30  FOUNDATIONS   OF   BOTANY 

SUBFAMILY   I.  —  LILIACE  JE  PROPER. 

Not  tendril-climbers,  rarely  dioecious. 

A. 

Styles  or  sessile  stigmas  3,  more  or  less  separate. 

Leaves  3-ranked,  strongly  nerved  and  plaited.     Flowers  some- 
what monoecious,  small.  Veratrum,  I. 
Leaves  flat,  lanceolate,  or  spatulate.    Flowers  dioecious,  showy. 

Chamselirium,  II. 
Leaves  grass-like.     Flowers  perfect,  showy.      Amianthium,  III. 

B. 

Style  undivided  (in  No.  XXIII,  3  sessile  stigmas}.     Plants  from  root- 
stocks. 

Leaves  perfoliate.     Flowers  solitary,  drooping,  yellow. 

Uvularia,  IV. 

Leaves  broad,  clasping.     Flowers  solitary  or  nearly  so,  drooping, 

yellow.  Oakesia,  V. 

Leaves  scale-like.     Thread-like  branches  borne  in  their  axils. 

Flowers  small,  bell-shaped.  Asparagus,  XVII. 

Leaves  several-many,  sessile   or  clasping,  alternate.     Flowers 

small,  6-parted,  white,  in   a  terminal  simple    or    compound 

raceme.  Smilacina,  XVIII. 

.Leaves   only   2-3,  sessile   or   slightly   petioled.     Flowers  very 

small,  4-parted,  solitary  or  in  a  small  terminal  cluster. 

Maianthemum,  XIX. 

Leaves  clasping.     Flowers  solitary  or  in  pairs,  greenish-white  or 
rose-purple,  borne  on  pedicels  abruptly  bent  near  the  middle. 

Streptopus,  XX. 

Leaves  nearly  sessile    or   partly    clasping.       Flowers    axillary, 
greenish,  on  pedicels  jointed  near  the  flower. 

Polygonatum,  XXI. 


MONOCOTYLEDONOUS   PLANTS  31 

Leaves  only  2,  directly  from  the  rootstock.     Flowers  in  a  raceme, 
bell-shaped,  white,  sweet-scented.  Convallaria,  XXII. 

Leaves  3,  netted-veined.     Flower  single,  large,  terminal. 

Trillium,  XXIII. 

C. 

Style  undivided.     Plants  from  fibrous  roots. 

Flowers  yellow  or  orange.  Hemerocallis,  VI. 

Flowers  white.  Yucca,  XVI. 

D. 

Style  usually  undivided.     Plants  from  coated  or  solid-looking  bulbs. 

Leafy-stemmed  plants.      Flowers  large,  solitary,  or  apparently 
umbelled.  Fritillaria,  IX. 

Apparently  stemless  plants. 

(a)  Plants  with  the  smell  of  onions  or  garlic.     Flowers 

umbelled.  Allium,  VII. 

(&)  Flower  solitary,  erect,  l^rge.  Tulipa,  X. 

(c)  Flower  solitary,  nodding.  Erythronium,  XT. 

(rf)  Flowers   racemed.     Perianth  with    hardly   any   tube. 

Stigma  a  single  knob.  Scilla,  XII. 

(e)  Flowers   racemed.      Perianth  with    hardly   any   tube. 

Stigma  3-cleft.  Camassia,  XIII. 

(f)  Flowers  corymbed.      Perianth  with  hardly  any  tube. 

Leaves  linear.  Ornithogalum,  XIV. 

(</)  Flowers   racemed.      Perianth   with    a   tube.       Leaves 

lance-linear.  Hyacinthus,  XV. 

E. 

Style  undivided.     Plants  from  scaly  bulbs.  Lilium,  VIII. 

SUBFAMILY   II.  —  SMILACE^E. 

Climbers,  often  tendril-bearing.     Flowers  dioecious.          Smilax,  XXIV. 


32  FOUNDATIONS   OF   BOTANY 


I.     VERATRUM,  Tourn. 

Simple-stemmed  perennials.  Koots  fibrous,  from  the  thick- 
ened base  of  the  stem,  poisonous,  emetic.  Leaves  3-ranked, 
plaited,  and  veiny.  Flowers  panicled,  greenish,  or  brownish. 
Sepals  6,  spreading,  nearly  free  from  the  ovary.  Stamens 
shorter  than  the  perianth,  and  inserted  on  its  base.  Ovary  of 
3  carpels  united  at  base.  Fruit  a  few-seeded  capsule,  splitting 
into  3  parts. 

1.  V.  viride,  Ait.     WHITE    HELLEBORE.    INDIAN   POKE.     Stem 
stout,  2—7  ft.  high,  very  leafy.     Flowers  very  numerous,  in  a  panicle, 
composed   of  spike-like   racemes.      Sepals    yellowish-green.      Wet 
meadows  and  brooksides. 

2.  V.  Woodii,  Robbins.     Stem  slender,  2-5  ft.  high,  not  very  leafy. 
Flowers  in  a  long,  narrow  panicle.     Sepals  greenish-purple  or  almost 
black.     Woods  and  dry  hillsides. 

II.     CHAMJELIRIUM,  Willd. 

Rootstock  short  and  thick,  bitter.  Stem  simple,  erect,  leafy, 
smooth.  Lower  leaves  spatulate  to  obovate,  the  stem-leaves 
narrower.  Flowers  small,  white,  in  a  spike-like  raceme, 
dio?cious.  Perianth  of  6  linear-spatulate  segments.  Stamens 
6,  filaments  longer  than  the  perianth.  Ovary  3-celled,  styles 
3.  Fruit  an  ovoid,  3-angled,  many-seeded  capsule.* 

1.  C.  carolinianum,  Willd.  UNICORN-ROOT,  DEVIL'S  BIT.  Stem 
furrowed,  staminate  plants  1-2  ft.  high,  pistillate  taller,  often  3  ft. 
or  more.  Lower  leaves  obovate,  clustered,  the  upper  small  and 
bract-like.  Staminate  racemes  slender  and  drooping,  the  pistillate 
erect.  Flowers  short-pediceled.  Capsule  3-valved,  seeds  linear- 
oblong,  winged  at  the  ends.  On  low  ground.* 

III.     AMIANTHIUM,  Gray. 

Stem  simple,  glabrous,  erect  from  a  bulbous  base.  Leaves 
long  and  slender.  Flowers  white,  in  a  simple  terminal  raceme, 
perfect.  Perianth  of  6  segments  which  are  sessile  and  gland- 
less.  Stamens  6,  inserted  in  the  base  of  the  perianth.  Ovary 
3-lobed,  3-celled,  fruit  a  dehiscent,  3-lobed  capsule,  the  lobes 
becoming  awl-shaped  by  the  persistent  style  bases ;  cells  few- 
seeded.* 


MONOCOTYLEDONOUS  PLANTS  33 

1.  A.  muscaetoxicum,  Gray.  FLY  POISON.  Bulb  ovoid  or  oblong. 
Stem  somewhat  angled  below,  1-3  ft.  high.  Lower  leaves  strap- 
shaped,  channeled,  the  upper  small  and  bract-like.  Raceme  dense, 
cylindrical,  pedicels  from  the  axils  of  minute  ovate  bracts.  Peri- 
anth segments  ovate,  white,  becoming  greenish,  nearly  as  long  as 
the  slender  stamens.  Styles  spreading.  Capsule  with  divergent 
lobes;  seeds  ovoid,  red.  In  rich  woods.* 


IV.     UVULARIA,  L. 

Bather  low  plants  with  short  rootstocks.  Leaves  alternate, 
broad,  and  parallel-veined.  Flowers  yellow  or  yellowish, 
drooping,  borne  singly  at  the'  end  of  the  forking  stem. 
Perianth  of  6  similar  and  separate  narrow  spatulate  sepals, 
each  grooved  and  nectar-bearing  inside  toward  the  base. 
Stamens  6,  with  linear  anthers,  which  are  much  longer  than 
the  filaments.  Style  3-cleft.  Pod  3-lobed,  3-celled,  few- 
seeded. 

1 .  U.  grandiflora.    LARGER  BELLWORT.    Leaves  oblong,  with  the 
base  clasping  the  stem  so  as  to  make  it  appear  to  run  through  the 
leaf  a  little  way  from  the  base ;  flowers  greenish- yellow,  l£  in.  long, 
anthers  obtuse.     A  leafy  plant,  1-2  ft.  high. 

2.  U.  perfoliata.     MEALY   BELLWORT.     Leaves  much  as  in  the 
preceding  species ;  flowers  very  pale  yellow,  with  shining  grains  on 
the  inner  surfaces  of  the  twisted  sepals;    anthers   sharp-pointed; 
plant  about  %  the  size  of  the  preceding. 

V.  OAKESIA,  Watson. 

Plants  with  much  the  aspect  of  the  preceding  genus,  but 
with  merely  sessile  leaves,  triangular  winged  pods,  and  slen- 
der creeping  rootstocks. 

1.  0.  sessilifolia.  WILD  OATS,  STRAW  LILIES.  Stem  slender, 
zigzag.  Leaves  lance-oval,  thin,  smooth,  pale  beneath,  1-1  £  in. 
long.  Flower  cream-color,  nearly  1  in.  long. 

VI.  HEMEROCALLIS,  L. 

Perennial,  from  a  fascicle  of  fleshy  roots.  Stem  erect, 
branched,  smooth.  Leaves  mostly  basal  and  linear.  Flowers 
on  branching  scapes,  large,  yellow  or  orange,  solitary  or 


34  FOUNDATIONS   OF   BOTANY 

corymbed,  perianth  funnel-form,  with  a  spreading  limb  much 
longer  than  the  tube.  Stamens  6,  inserted  in  the  top  of  the 
tube,  shorter  than  the  lobes,  curved  upward.  Ovary  3-celled, 
many-ovuled,  style  longer  than  the  stamens,  curved  upward, 
stigma  knobbed.  Fruit  a  3-celled,  3-angled  capsule.* 

1.  H.  fulva,  L.  DAY  LILY.  Scapes  stout,  branched  above,  with  a 
few  bract-like  leaves,  smooth,  3-5  ft.  high.  Leaves  very  long,  strap- 
shaped,  acute,  channeled.  Flowers  short-pediceled,  tawny-yellow, 
perianth  lobes  oblong,  netted-veined,  lasting  only  one  day.  Intro- 
duced from  Asia  and  common  in  old  gardens.* 

VH.     ALLIUM,  L. 

Stemless  herbs  from  coated  bulbs  with  the  characteristic 
odor  of  onions.  Bulbs  solitary  or  clustered.  Leaves  narrowly 
linear  or  slender-tubular,  with  a  bloom.  Flowers  small  on 
slender  pedicels,  in  terminal  umbels  on  naked  scapes,  the 
umbels  often  bracted  or  enclosed  in  a  spathe.  Perianth 
6-parted,  persistent ;  stamens  6,  inserted  on  the  base  of  the 
perianth,  filaments  filiform  or  dilated  below.  Ovary  sessile, 
3-celled.  Style  thread-like,  jointed ;  stigma  entire.  Fruit  a 
3-celled,  3-valved,  few-seeded  capsule.  Flowers  sometimes 
changed  into  bulblets.* 

1.  A.  canadense,  L.     MEADOW  GARLIC.     Bulbs  ovoid,  the  outer 
coats  of  white  and  thin,  dry,  netted  fibers.     Leaves  narrowly  linear, 
flat,  or  concave  above.     Scape  cylindrical,  1  ft.  high.     Bracts  of  the 
umbel  2-3,  ovate,  acuminate ;    umbel    consisting  mostly  of  sessile 
bulblets.     The  few  flowers    long-pediceled,  rose-colored.     Perianth 
about  as  long  as  the  stamens.     Filaments  dilated  below.     Capsule 
shorter  than  the  perianth,  6-toothed,  ovules  2  in  each  cell.    On  moist 
soil.* 

2.  A.  striatum,  Jacq.     STRIPED  WILD  ONION.     Bulbs  clustered, 
outer  coat  membranaceous.     Leaves  linear,  concave,  striate  on  the 
back.     Scape  6-12  in.  high.     Umbel  3— 10-flowered,  bracts  2,  pedicels 
1-2  in.  long.     Perianth  nearly  white,  longer  than  the  stamens,  the 
outer  segments  green-keeled  on  the  back.     Capsule    not   toothed, 
seeds  several  in  each  cell.     Low  pine  barrens.* 

•  3.  A.  vineale,  L.  FIELD  GARLIC.  Bulb  mostly  solitary.  Leaves 
cylindrical,  hollow,  very  slender.  Scape  slender,  sheathed  below  the 
middle  by  the  bases  of  the  leaves.  Umbels  often  crowded  with 
bulblets.  A  troublesome  weed  in  moist  meadows  and  fields  east- 
ward, giving  milk  a  strong  flavor  of  onions  or  garlic. 


MONOCOTYLEDONOUS   PLANTS  35 


VIII.     LILIUM,  L. 

Perennial,  from  scaly  bulbs,  stem  erect,  leafy,  usually  tall 
and  slender.  Leaves  sessile,  scattered,  or  whorled.  Flowers 
large,  erect,  or  drooping.  Perianth  corolla-like,  deciduous. 
Segments  6,  spreading  or  recurved  above,  sessile  or  clawed, 
each  with  a  nectar-bearing  groove  near  the  base.  Stamens  6, 
elongated,  anthers  linear,  versatile.  Ovary  3-celled,  many- 
ovuled,  style  long  and  slender,  stigma  3-lobed.  Fruit  a  3-celled, 
dehiscent,  many-seeded  capsule. 

1.  L.  longiflorum,  Thunb.     LONG-FLOWERED  WHITE  LILY.    Stem 
1-3  ft.  high.     Leaves  thick,  lanceolate,  scattered.     Flower  single, 
pure  white,  funnel-shaped,  5-6  in.  long.     Var.  eximium,  the  Easter 
lily,  bears  several  very  showy  and  sweet-scented  flowers. 

2.  L.  philadelphicum,  L.     WILD  RED  LILY.     Stem  2-3  ft.  high. 
Leaves  linear-lanceolate,  the  upper  ones  generally  whorled.     Flower 
usually  solitary  (sometimes  2  or  3),  erect,  reddish-orange,  with  tawny 
or  purplish  spots  inside.     Sepals  with  claws.     Dry  or  sandy  ground, 
borders  of  thickets,  etc. 

3.  L.  canadense,  L.    WILD  YELLOW  LILY,  MEADOW  LILY.    Stem 
2-5  ft.  high.     Leaves  lanceolate,  3-nerved,  the  margins  and  nerves 
roughish  with  short  hairs,  whorled.     Flowers  usually  3,  sometimes 
more  numerous,  all  nodding,  on  peduncles  3-6  in.  long,  yellow  or 
orange,  with  dark-purple  or  brown  spots  inside.     Sepals  without 
claws,  recurved.     Moist  meadows  and  borders  of  woods. 


IX.     FRITILLARIA,  Tourn. 

Leafy-stemmed  perennials,  from  scaly  or  coated  bulbs. 
Flowers  single  or  several,  nodding.  Perianth  bell-shaped,  a 
nectar-bearing  spot  above  the  base  of  each  division.  Stamens 
as  long  as  the  petals. 

1.  F.  Meleagris,  L.     GUINEA-HEN   FLOWER.     Stem   1  ft.  high. 
Leaves  linear,  alternate,  channeled.     Flower  usually  single,  large, 
purplish,  checkered  with  blue  and  purple    or  yellow.      Cultivated 
from  Europe. 

2.  F.  imperialis,  L.   CROWN  IMPERIAL.    Stem  3-4  ft.  high.    Leaves 
abundant  in  whorls  about  the  middle  or  lower  part  of  the  stem,  lan- 
ceolate or  lance-oblong.     Flowers  several,  large,  yellow  or  red,  in  an 
umbel-like  cluster  beneath  the  terminal  crown  of  leaves.     Cultivated 
from  Asia. 


36  FOUNDATIONS   OF  BOTANY 


X.     TULIPA,  Tourn. 

Stemless  herbs  from  coated  bulbs.  Leaves  sessile.  Scape 
simple.  Flower  solitary,  erect.  Perianth  bell-shaped.  Stamens 
short,  awl-shaped,  with  broadly  linear  anthers.  Style  short, 
stigma  thick,  3-lobed.  Ovary  and  pod  triangular. 

1.  T.  gesneriana,  L.  COMMON  TULIP.  Leaves  3-6,  ovate-lanceo- 
late, close  to,  the  ground.  Flower  large,  on  a  smooth  peduncle,  color 
red,  yellow,  white,  or  variegated.  Cultivated  from  Asia  Minor. 
Many  garden  varieties  exist. 

XI.     ERYTHRONIUM,  L. 

Nearly  stemless  herbs,  arising  from  rather  deeply  buried 
bulbs.  Leaves  2,  long  and  smooth,  with  underground  petioles. 
Scape  arising  from  between  the  bases  of  the  leaves.  Flower 
commonly  single,  nodding. 

1.  E.    americanum,   Ker.      YELLOW   ADDER'S-TONGUE.      Leaves 
mottled.     Flowers   handsome.     Perianth  light   yellow,  style    club- 
shaped,  stigmas  united. 

2.  E.   albidum,   Nutt.     WHITE    DOG'S-TOOTH    VIOLET.      Leaves 
not  much  mottled.     Perianth  bluish-white.     Stigmas  3,  short  and 
spreading. 

XH.     SCILLA,  L. 

Perennial  stemless  herbs  from  coated  bulbs.  Leaves  linear. 
Flowers  racemed  on  a  scape,  generally  blue.  Divisions  of  the 
perianth  1-nerved,  parted  almost  to  the  base.  Filaments  6, 
often  broad  at  the  base.  Style  slender,  with  a  knob-like 
stigma.  Ovary  3-angled,  3-celled. 

1.  S.  sibirica,  Andr.  SIBERIAN  SQUILL.  Scapes  3-8  in.  high, 
several  from  each  bulb,  2-3-flowered.  Leaves  2-4,  narrowly  strap- 
shaped.  Flowers  intense  blue,  short-peduncled,  often  nodding. 
Cultivated  from  Russia  and  Siberia.  • 

XIII.    CAMASSIA,  Lindl. 

Stemless  herbs,  from  coated  bulbs.  Leaves  linear.  Flowers 
racemed,  on  a  scape.  Perianth  of  6  blue  or  purple  spreading 
sepals.  Stamens  with  thread-like  filaments,  from  the  base  of 
the  perianth.  Style  thread-like,  ending  in  a  knobbed  stigma. 
Capsule  3-angled,  3-celled,  several-seeded. 


MONOCOTYLEDONOUS  PLANTS  37 

1.  C.  Fraseri,  Torr.  WILD  HYACINTH.  Leaves  keeled,  weak, 
shorter  than  the  scape.  Flowers  in  a  long-bracted  raceme,  pale 
blue.  River  bottoms  and  other  damp,  rich  soil. 

XTV.    ORNITHOGALUM,  Tourn. 

Stemless  herbs  from  coated  bulbs.  Leaves  linear,  fleshy. 
Scape  erect.  Flowers  in  corymbs  or  racemes,  bracted.  Peri- 
anth .segments  6,  white,  nerved,  persistent.  Stamens  6, 
hypogynous,  slender.  Filaments  flattened.  Ovary  sessile, 
3-celled,  few-ovuled.  Fruit  a  roundish,  3-angled  capsule, 
seeds  black.* 

1.  0.  umbellatum,  L.  STAR  OF  BETHLEHEM.  Bulb  ovoid,  mem- 
branous-coated. Leaves  numerous,  linear,  fleshy,  mid-vein  nearly 
white,  as  long  as  the  scape.  Scape  slender,  6-12  in.  high.  Flowers 
opening  in  sunshine,  long-pediceled.  Bracts  linear-lanceolate,  about 
as  long  as  the  pedicels.  Perianth  segments  oblong-lanceolate,  white 
with  a  green  stripe  on  the  back,  twice  the  length  of  the  stamens. 
Introduced  from  Europe ;  very  common  about  old  gardens.* 

XV.    HYACINTHUS,  L. 

Stemless  herbs  from  coated  bulbs.  Leaves  linear,  fleshy. 
Flowers  in  an  erect  spike,  pediceled,  bracted.  Perianth 
tubular  below,  lobed  and  spreading  above.  Stamens  short, 
included.  Style  short,  stigma  knobbed.  Ovary  3-celled, 
rnany-ovuled.* 

1.  H.  orientalis,  L.  HYACINTH.  Leaves  lance-linear,  thick  and 
fleshy,  smooth.  Scape  erect,  many-flowered.  Segments  united  about 
half  their  length,  white,  blue,  or  red.  Filaments  very  short.  Ovary 
rarely  maturing  seed.  Common  in  cultivation.* 

XVI.    YUCCA,  L. 

Plants  with  woody  and  leafy  stems.  Leaves  numerous, 
rigid,  spine-pointed,  persistent.  Flowers  in  large  terminal 
racemes  or  panicles,  bracted,  nodding.  Perianth  bell-shaped, 
segments  6,  nearly  alike,  deciduous.  Stamens  6,  filaments 
thickened  above,  often  papillose.  Anthers  small.  Ovary 
sessile,  3-celled,  or  becoming  6-celled,  3-angled,  many-ovuled. 
Fruit  an  oblong,  3-angled,  many-seeded,  dehiscent  capsule, 
or  fleshy  and  indehiscent.* 


38  FOUNDATIONS   OF   BOTANY 

1.  Y.  filamentosa,  L.  SPANISH  DAGGER.  Stem  stout,  4-12  in. 
high.  Leaves  linear  or  linear-lanceolate,  slender-pointed,  narrowed 
above  the  spreading  and  clasping  base,  spreading  or  recurved,  smooth, 
with  loose,  thread-like  filaments  on  the  margins.  Panicle  elongated, 
with  bract-like  leaves  on  the  scape,  widely  branched,  downy-hairy 
above,  3-6  ft.  high.  Perianth  white,  bell-shaped,  2  in.  wide.  Cap- 
sule oblong,  angles  rounded,  sides  furrowed,  at  length  3-valved  and 
dehiscent.  In  sandy  soil,  and  often  cultivated  for  ornament.* 

XVII.    ASPARAGUS,  Tourn. 

Stem  from  fleshy  fibrous  roots,  erect,  branched,  branches 
slender,  with  thread-like  branchlets  in  the  axils  of  scales  which 
take  the  place  of  leaves.  Flowers  small,  solitary,  or  racemed. 
Perianth  6-parted,  segments  distinct  or  slightly  united.  Sta- 
mens 6,  perigynous,  filaments  thread-like.  Ovary  3-celled, 
6-ovuled,  style  short,  slender,  stigmas  3,  recurved.  Fruit  a 
berry.* 

1.  A.  officinalis,  L.  ASPARAGUS.  Stem  succulent  and  simple,  with 
fleshy  scales  when  young,  becoming  taller,  more  woody  and  widely 
branched  when  old.  Flowers  axillary,  solitary,  or  2  or  3  together  on 
slender,  jointed,  drooping  pedicels,  greenish,  segments  linear.  Berry 
red,  few-seeded.  Introduced  from  Europe,  common  in  cultivation, 
and  often  escaped.* 

XVm.    SMILACINA,  Desf. 

Perennial,  simple-stemmed  herbs,  with  rootstocks.  Leaves 
usually  sessile,  nerved,  alternate.  Flowers  white,  in  a  ter- 
minal raceme.  Perianth  spreading,  6-parted.  Stamens  6, 
springing  from  the  base  of  the  perianth.  Filaments  slender. 
Anthers  short,  facing  inward.  Ovary  3-celled,  6-ovuled.  Style 
short  and  stout,  with  a  somewhat  3-lobed  stigma.  Fruit  a 
1-2-seeded  berry. 

1.  S.  racemosa,  Desf.     FALSE  SPIKENARD.     A  showy  plant  with 
curved  stem  1-3  ft.   high,   downy  throughout.     Leaves  abundant, 
oval  or  ovate-lanceolate,  taper-pointed.     Flowers  small,  in  a  com- 
pound raceme.     Berries  pale  red,  speckled  with  dark  red  or  purple. 
Moist  thickets. 

2.  S.  stellata,  Desf.     Plant  1  ft.  or  less  in  height,  nearly  smooth. 
Leaves  broadly  lanceolate,  acute,  clasping.     Flowers  few,  larger  than 
in  No.  1,  in  a  simple  raceme.     Berries  very  dark   red.     Along  river 
banks. 


MONOCOTYLEDONOUS  PLANTS  39 


XIX.     MAIANTHEMUM,  Wigg. 

Stem  low.  Leaves  2-3,  lanceolate  or  ovate,  with  a  heart- 
shaped  base.  Flowers  small,  white,  solitary,  or  in  a  simple 
raceme.  Perianth  4-parted.  Stamens  4.  Ovary  2-celled. 
Stigma  2-lobed. 

1.  M.  canadense,  Desf.  TWO-LEAVED  SOLOMON'S  SEAL,  WILD 
LILY-OF-THE-VALLEY.  Plant  3-6  in.  high.  Leaves  very  short- 
petioled.  Fruit  a  globular  or  ovoid  berry,  whitish,  with  brownish- 
red  blotches.  Woods  and  shaded  banks  N. 


XX.    STREPTOPUS,  Michx. 

Herbs  with  forking  stems  from  a  creeping  rootstock.  Leaves 
clasping.  Flowers  small,  borne  singly  or  in  pairs  on  peduncles 
which  arise  above  the  leaf-axils  and  which  are  sharply  bent 
or  twisted  near  the  middle.  Anthers  arrow-shaped.  Ovary 
3-celled,  ripening  into  a  red,  many-seeded  berry. 

1.  S.  amplexifolius,  D.  C.     LIVER-BERRY.     Stem  smooth,  2  ft.  or 
more   high.      Leaves   smooth-margined.      Flowers   greenish-white. 
Damp  woods. 

2.  S.  roseus,  Michx.    LIVER-BERRY,  JACOB'S  LADDER.     Branches 
with  a  few  bristly  hairs.     Lower  leaves  margined  with  fine  bristles. 
Flowe'rs  reddish  or  purplish.     Cold,  damp  woods  N. 


XXI.    POLYGONATUM,  Tourn. 

Rootstock  creeping,  jointed,  scarred.  Stems  simple,  erect, 
scaly  below,  leafy  above.  Leaves  alternate,  oval,  or  oblong. 
Flowers  on  axillary,  1-4-flowered,  drooping,  jointed  peduncles. 
Perianth  tubular,  6-cleft.  Stamens  6,  included,  inserted  about 
the  middle  of  the  tube.  Anthers  arrow-shaped.  Ovary 
3-celled,  many-ovuled,  style  slender,  stigmas  knobbed  or 
3-lobed.  Fruit  a  few-seeded  berry.* 

1.  P.  biflorum,  Ell.  HAIRY  SOLOMON'S  SEAL.  Stem  simple,  erect, 
arched,  nearly  naked  below,  1-2  ft.  high.  Leaves  2-ranked,  sessile 
or  clasping,  3-7-nerved,  smooth  above,  pale  and  downy  beneath. 
Peduncles  short,  1-4,  often  2-flowered.  Perianth  greenish,  1-2  in. 
long.  Filaments  thread-shaped,  roughened.  Berry  dark  blue. 
Shady  banks.* 


40  FOUNDATIONS   OF   BOTANY 

2.  P.  giganteum,  Dietrich.  SMOOTH  SOLOMON'S  SEAL.  Stem 
simple,  stout,  curving  above,  3-8  ft.  high.  Leaves  lanceolate  to  ovate, 
many-nerved,  partly  clasping,  smooth  on  both  sides.  Peduncles  nearly 
half  as  long  as  the  leaves,  2-6-flowered.  Perianth  green ish-yellow, 
|  in.  long.  Filaments  smooth.  Berry  blue,  \  in.  in  diameter.  In 
rocky  woods  and  along  streams.* 

XXII.     CONVALLARIA,  L. 

Low,  smooth,  stemless,  perennial  herbs.  Leaves  2,  oblong, 
with  long  petioles,  from  a  slender,  creeping  rootstock.  Scape 
slender,  angled,  enclosed  at  the  base  by  the  leaf-stalks.  Flowers 
racemed,  white,  drooping.  Perianth  bell-shaped,  with  recurved 
lobes.  Stamens  borne  on  the  base  of  the  perianth.  Ovary 
3-celled,  ripening  into  a  few-seeded  red  berry. 

1.  C.  majalis,  L.  LILY-OF-THE-VALLEY.  A  familiar  garden  flower, 
cultivated  from  Europe,  and  also  found  wild  in  mountain  woods 
from  Virginia  to  Georgia. 

XXIH.    TRILLIUM,  L. 

Low  herbs  with  the  stem  springing  from  a  short  rootstock. 
Leaves  3,  large,  netted-veined,  in  a  whorl.  Flower  large,  ter- 
minal. Perianth  of  6  parts,  the  3  sepals  unlike  the  3  petals 
in  color  and  in  texture.  Stamens  6,  with  the  linear  anthers 
usually  opening  inward,  longer  than  the  filaments.  Stigmas 
3,  sessile,  spreading  at  the  tips.  Ovary  3  or  6-angled,  3-celled, 
many-seeded.  Fruit  a  roundish,  many-seeded  purple  berry. 

1.  T.  sessile,  L.     Rootstock  erect  or  ascending,  corm-like.     Stem 
slender,  1-8  in.  high.     Leaves  broadly  oval,  obtuse  or  acute  at  the 
apex,  rounded  and  sessile  at  the  base,  3-5-nerved,  smooth,  bright 
green,  not  mottled.     Flowers  sessile,  sepals  lanceolate,  f-1  in.  long, 
petals  purple,  elliptical,  about  the  length  of  the  sepals.     Stamens 
half  the  length  of  the  petals.     Styles  elongated,  straight.     In  rich 
woods.* 

2.  T.  Underwoodii,  Small.     UNDERWOOD'S  WAKE-ROBIN.     Root- 
stock  horizontal,  stem  stout,  4—12  in.  high.     Leaves  ovate-lanceolate 
to  broadly  ovate,  acute  or  short  taper-pointed  at  the  apex,  rounded 
and  sessile  at  the  base,  wavy  on  the  margins,  3-5-nerved,  smooth, 
prominently  mottled  with  different  shades  of  green.    Flowers  sessile. 
Sepals  lanceolate,  l£-2  in.  long,  often  purplish  green.    Petals  purple, 
lanceolate  to  oblanceolate,  2-3  in.  long.     Stamens  \-\  the  length 
of  the  petals.     Style  very  short,  stigmas  recurved,     Fruit  an  ovoid 
berry.     In  rich  woods,* 


MONOCOTYLEDONOUS  PLANTS  41 

3.  T.  erectum,  L.     SQUAWROOT,  BENJAMIN.     Rootstock   rather 
upright,  large  and  stout.     Leaves  broadly  diamond-shaped,  tapering 
to  a  short  point.     Pedicel  1-3  in.  long,  not  quite  erect.     Petals  ovate 
to  lanceolate,  much  broader  than  the  sepals,  of  a  rich  brownish- 
purple  or  sometimes  white  or  pale.     Stigmas   distinct,  stout,  and 
spreading.     The  disagreeable  scent  of  the  flower  has  given  rise  to 
several  absurd  popular  names  for  it.     In  rich  woods. 

4.  T.    grandiflorum,    Salisb.       LARGE-FLOWERED    WAKE-ROBIN. 
Rootstock  horizontal,  stem  slender,  12-18  in.  high.    Leaves  rhombic- 
ovate,  taper-pointed   at   the    apex,  rounded  and  sessile  or  slightly 
peduncled  at  the  base,  smooth  and  with  a  bloom,  5-7-nerved,  bright 
green.     Peduncle  longer  than  the  erect  or  slightly  declined  flower. 
Sepals  lanceolate-acute,  1-1^  in.  long.    Petals  white,  fading  to  pink, 
longer  than  the  sepals.     Stamens  less  than  half  the  length  of  the 
petals.    Style  short,  stigmas  recurved.    Fruit  a  black,  roundish  berry. 
In  rich  woods.* 

5.  T.  nivale,  Riddell.     DWARF  WHITE  TRILLIUM.    Plant  2-4  in. 
high.     Leaves  petioled,  oval  to  ovate.     Flower  white,  erect.     Petals 
^-1^  in.  long,  ovate-spatulate.     Rich,  damp  woods,  blooming  with 
the  very  earliest  spring  flowers. 

6.  T.  erythrocarpum,  Michx.     PAINTED  TRILLIUM.     Plant  8-12 
in.  high.     Roofstock  oblique  to  the  rest  of  the  stem,  rather  small ; 
roots  long  and  fibrous.     Leaves  ovate,  taper-pointed.     Petals  white, 
penciled   at   the  base,  with  purple   stripes,  lance-ovate,  somewhat 
recurved,  wavy.     Cold  woods,  especially  N. 

XXIV.    SMILAX,  Tourn. 

Mostly  woody  vines,  usually  with  prickly  steins,  climbing  by 
tendrils.  Rootstock  often  large  and  tuberous.  Leaves  alter- 
nate, prominently  nerved,  netted-veined,  petioled,  stipules 
replaced  by  persistent  tendrils.  Flowers  regular,  dioecious, 
small,  greenish,  in  axillary  umbels.  Perianth  bell-shaped, 
segments  6.  Stamens  6,  distinct.  Ovary  3-celled,  3-6-ovuled, 
stigmas  1-3,  sessile  or  nearly  so.  Fruit  a  1-6-seeded  globose 
berry. 

1.  S.  herbacea,  L.  CARRION-FLOWER.  Stem  herbaceous,  erect, 
simple  or  branched,  not  prickly,  1-3  ft.  high.  Leaves  few,  ovate, 
acute,  and  mucronate  at  the  apex,  somewhat  heart-shaped  at  the 
base,  5-7-nerved,  thin,  smooth  above,  downy  below,  the  upper  some- 
times whorled  and  the  lower  bract-like  ;  petiole  short.  Peduncles  as 
long  as  the  leaves,  growing  from  below  the  petiole.  Umbel  many- 
flowered,  flowers  carrion-scented.  Berry  blue-black,  2-4-seeded.  Dry, 
fertile  soil.* 


42  FOUNDATIONS  OF  BOTANY 

2.  S.   glauca,  Walt.     GREEN-BRIER.     Stem   cylindrical,   slender, 
with  scattered  prickles,  branches  angled,  and  usually  without  prickles. 
Leaves  ovate  or  subcordate,  pointed  at  the  apex,  mostly  5-nerved, 
smooth,    white    beneath,   with  a   bloom,  margin    entire.     Peduncle 
flattened,  2-3  times   as  long  as  the  petiole,  few-flowered.     Berry 
black,  3-seeded.     Margin  of  swamps.* 

3.  S.  Bona-Nox,  L.     BAM  BOO- VINE.     Stem  stout,  cylindrical,  or 
slightly  angled,  scurfy  when  young,  armed  with   numerous   stout 
prickles.     Branches  4-angled,  usually  unarmed.     Leaves  triangular, 
ovate,  or  often  halberd-shaped,  5-7 -ribbed,  smooth  on  both  sides  and 
often  discolored,  margins  usually  fringed  with  fine  prickles.    Pedun- 
cles twice  as  long  as  the  petioles,  flattened.     Umbels  many-flowered, 
pedicels  short.    Berries  8-20  in  a  cluster,  black,  1-seeded.    In  swamps 
and  thickets.* 

4.  S.    Walteri,    Pursh.       GREEN-BRIER.      Stem    low,    with    few 
prickles,  2-5  ft.  long,  branches  slightly  4-angled,  unarmed.     Leaves 
oblong-lanceolate  to  oval,  obtuse  or  acute  at  the  apex,  rounded  or 
cordate  at  the  base,  5-ribbed,  smooth.     Peduncles  flattened,  about  as 
long  as  the  petioles  and  pedicels.     Berry  bright  red,  ripening  the 
first  year.     Wet  pine  barrens.* 

5.  S.    rotundifolia,    L.      GREEN-BRIER,    CAT-BRIER,    DOG-BRIER, 
HORSE-BRIER,  WAIT-A-BIT.      Stem  green,  strong  ;  branchlets,  and 
sometimes  the  branches,  4-angled,  armed  with  stout  hooked  prickles. 
Leaves  ovate  or  round-ovate,  with  a  slightly  heart-shaped  base  and 
an  abruptly  pointed  tip.     Berries  black,  with  a  bloom.     Thickets, 
the  commonest  species  N.  E. 


11.    AMARYLLIDACEJE.     AMARYLLIS  FAMILY. 

Mostly  smooth  perennial  herbs,  from  bulbs.  Leaves  radi- 
cal, with  no  distinction  between  petiole  and  blade.  Flowers 
borne  on  a  scape,  nearly  or  quite  regular.  Stamens  6. 
Style  1.  Tube  of  the  6-parted,  corolla-like  perianth  adnate 
to  the  3-celled  ovary.  Capsule  3-celled,  several-many-seeded. 

I.     ZEPHYRANTHES,  Herb. 

Stemless,  from  a  coated  bulb.  Leaves  linear,  fleshy.  Scape 
erect,  1-few-flowered.  Flowers  large,  erect,  or  declined,  sub- 
tended by  a  1-2-leaved  spathe.  Perianth  6-parted,  naked  in 
the  throat,  tube  short,  segments  petal-like,  spreading.  Stamens 
free,  anthers  versatile.  Ovary  3-celled,  many-ovuled.  Style 


MONOCOTYLEDONOUS   PLANTS  43 

elongated,   declined.     Stigma  3-cleft.     Fruit  a  many-seeded, 
3-valved  capsule,  seeds  black,  compressed,  or  angled.* 

1.  Z.  Atamasco,  Herb.  ATAMASCO  LILY.  Bulbs  about  1  in.  in 
diameter.  Leaves  narrow,  concave  above,  smooth,  usually  longer 
than  the  scape.  Scape  6-12  in.  high,  1-flowered.  Spathe  1-leaved, 
2-cleft.  Flowers  2—3  in.  long,  white,  tinged  with  pink  or  purple, 
bell-shaped,  short-peduncled.  Stamens  longer  than  the  tube,  shorter 
than  the  style.  Capsule  depressed-globose,  seeds  angled.  In  rich, 
damp  soil,  often  cultivated.* 


II.    NARCISSUS,  L. 

Scapes  with  1-several  flowers  from  a  thin,  dry  spathe. 
Flowers  with  a  cup-shaped  or  other  crown  on  the  throat  of 
the  perianth  ;  tube  of  the  perianth  somewhat  cylindrical,  the 
6  divisions  of  the  limb  widely  spreading.  Stamens  6,  inserted 
in  the  tube. 

1.  N.  Pseudo-narcissus,  L.     DAFFODIL,  DAFFY,  EASTER-FLOWER. 
Scape  short,  bearing  1  large  yellow  flower  ;  tube  of  perianth  short 
and  wide,  crown  with  a  crimped  margin.     Cultivated  from  Europe. 

2.  N.   Tazetta,  var.  orientalis.      CHINESE  SACRED  LILY.     Bulb 
large,  often  with  many  smaller  ones  attached  to  its  base.     Scape 
1  ft.  or  more  high.     Flowers  several,  umbeled,  fragrant.     Perianth 
white  or  nearly  so,  the  crown  rather  spreading,  finely  scalloped, 
yellow  or  orange.     Cultivated  from  China. 

3.  N.  poeticus,  L.     POET'S  NARCISSUS.     Scape  1-flowered.     Peri- 
anth pure  white,  the  crown  very  narrow,  edged  with  pink.     Culti- 
vated from  S.  Europe. 

III.    HYPOXIS,  L. 

Small,  stemless  herbs.  Leaves  grass-like,  hairy,  from 
a  solid  bulb.  Scapes  thread-like,  few-flowered.  Perianth 
6-parted,  wheel-shaped,  the  3  outer  divisions  greenish  on  the 
outside,  the  whole  perianth  withering  on  the  pod.  Seeds 
numerous. 

1.  H.  erecta,  L.  STAR-GRASS.  Leaves  longer  than  the  scape, 
both  sparsely  set  with  long,  soft  hairs.  Scape  3-8  in.  high.  Flowers 
1-4,  about  ^  in.  across,  yellow.  Common  in  meadows  and  dry 
woods. 


44 


FOUNDATIONS   OF  BOTANY 


I,  flower  ;  II,  seed,  longitudinal  section  ;  III,  flower  with  outer  segments  of 
perianth  removed  ;  stlg.,  stigma,  ov.,  ovary- 


FIG.  7.  —  Iris. 


M 


I,  flower,  longitudinal  section,  ov.,  ovary  ;  II,  diagram,  showing  stigmas 
ppposite  the  stamens  ;  III,  capsule,  splitting  between  the  partitions. 


MONOCOTYLEDONOUS   PLANTS  45 


12.    IRIDACEJE.     IRIS  FAMILY. 

Perennial  herbs  from  bulbs,  corms,  or  rootstocks.  Leaves 
2-ranked,  equitant.  Flowers  perfect,  regular  or  irregular,  each 
subtended  by  two  bracts.  Perianth  6-parted,  the  tube  adher- 
ent to  the  ovary,  the  segments  in  2  series  of  3  each,  equal,  or 
the  inner  ones  smaller.  Stamens  3,  distinct  or  united,  oppo- 
site the  outer  segments.  Ovary  forming  a  3-celled,  3-angled, 
3-valved,  many-seeded,  dehiscent  capsule.* 

I.    CROCUS,  L.    Crocus. 

Leaves  radical.  Flowers  sessile  on  the  corm.  Tube  of  the 
perianth  very  long  and  slender,  its  divisions  all  alike  or 
nearly  so.  Stigmas  3-cleft. 

1.  C.  vernus.  SPRING  CROCUS.  Leaves  linear.  Stigmas  short. 
Flowers  white,  blue,  or  purple.  Our  earliest  garden  flower.  Culti- 
vated from  Europe. 

H.    IRIS,  Tourn. 

Rootstock  thick,  creeping,  branching,  horizontal,  sometimes 
tuberous.  Stems  erect,  simple,  or  branched.  Leaves  linear  or 
sword-shaped.  Flowers  showy,  epigynous,  the  outer  perianth 
segments  spreading  or  recurved,  often  bearded  within,  the 
inner  segments  usually  smaller  and  erect.  Stamens  inserted 
in  the  base  of  the  outer  segments.  Style  deeply  3-parted,  the 
divisions  broad  and  petal-like,  covering  the  stamens.  Fruit 
an  oblong  or  oval,  3  or  6  angled,  many-seeded  capsule.* 

1.  I.  versicolor,  L.     LARGE  BLUE  FLAG.     Rootstock  thick,  hori- 
zontal.    Stem  cylindrical,  smooth,  simple  or  branched,  leafy,  2-3  ft. 
high.     Leaves  linear,  sword-shaped,  finely  nerved,  with  a  bloom,  the 
lower  l£-2  ft.  long,    the   upper  snorter.      Bracts  longer  than  the 
pedicels.     Flowers  terminal,  single,  or  few  together,  blue  variegated 
with   white,  yellow,  and  purple,  perianth    segments   not   bearded, 
the  inner  ones  smaller.     Ovary  3-angled,  longer  than  the  inflated 
perianth  tube.     Capsule  oblong,  slightly  lobed,  seeds  2  rows  in  each 
cell.     In  wet  places.* 

2.  I.  germanica,  L.      FLEUR-DE-LIS.      Rootstock   thick,    matted. 
Stem  stout,  branched,  leafy,   2-3  ft.   high.      Leaves   strap-shaped, 


46  FOUNDATIONS   OF  BOTANY 

acute,  erect,  shorter  than  the  stem,  bracts  scarious.  Flowers  sessile, 
large  and  showy,  blue,  variegated  with  white  and  yellow,  sometimes 
nearly  all  white,  outer  segments  large,  recurved,  bearded,  the  inner 
narrower,  erect,  or  arched  inward.  Introduced  from  Europe  ;  com- 
mon in  gardens  and  naturalized  in  many  places.* 

3.  I.  fulva,  Ker.  YELLOW  FLAG.  Rootstock  fleshy.  Stem  sim- 
ple or  branched,  grooved,  1-angled  below,  bearing  2-3  leaves,  2-3  ft. 
high.  Leaves  linear,  sword-shaped,  with  a  bloom,  shorter  than  the 
stem,  bracts  small.  Pedicels  short,  flowers  axillary  and  terminal, 
dull  yellow  or  reddish-brown,  variegated  with  blue  and  green,  peri- 
anth segments  not  bearded.  Style  branches  but  little  exceeding 
the  stamens,  ovary  about  as  long  as  the  inflated  perianth  tube. 
Capsule  ovate,  6-angled.  Swamps  and  wet  places.* 


HI.     SISYRHINCHIUM,  L. 

Small,  grass-like  perennials.  Stems  erect,  flattened,  or 
winged.  Boots  fibrous.  Leaves  linear  or  lanceolate.  Flowers 
small,  blue,  quickly  withering,  in  terminal  2-bracted  umbels. 
Perianth,  corolla-like,  of  6  bristle-pointed  segments,  tube 
nearly  or  wholly  lacking.  Stamens  3,  completely  rnonadel- 
phous.  Stigmas  3,  thread-like.  Fruit  a  nearly  globular 
3-angled  capsule.  Species  too  difficult  for  the  beginner. 

13.    ORCHIDACEJE.     ORCHIS  FAMILY. 

Perennial  herbs  with  simple  stems,  often  arising  from  bulbs 
or  tubers.  Leaves  simple,  usually  alternate  and  entire.  Flow- 
ers perfect,  generally  showy,  often  extraordinarily  irregular. 
Perianth  of  6  divisions,  adnate  to  the  1-celled  ovary.  Stamens 
1  or  2,  united  with  the  pistil ;  pollen  of  comparatively  few 
grains  held  together  in  masses  by  cobweb-like  threads.  Ovary 
1-celled,  containing  many  (sometimes  more  than  a  million) 
very  minute  ovules. 

The  family  is  a  difficult  one,  and  most  of  the  genera  are 
so  rare  that  specimens  should  not  be  collected  in  large  num- 
bers for  class  study.  Two  of  the  most  familiar  genera  are 
Cypripedium,  or  lady's  slipper,  and  Spiranthes,  or  lady's  tresses. 
Many  of  the  genera  are  tropical  air-plants  like  Part  I,  Fig.  13. 


DICOTYLEDONOUS   PLANTS  47 


SUBCLASS   II.  —  DICOTYLEDONOUS    PLANTS. 

Stems  composed  of  .bark,  wood,  and  pith ;  the  fibro-vasciilar 
bundles  in  rings  ;  in.  woody  stems  which  live  over  from  year 
to  year,  the  wood  generally  in  annual  rings,  traversed  at  right 
angles  by  medullary  rays.  Leaves  netted-veined.  Parts  of 
the  flower  usually  in  fours  or  fives.  Cotyledons  2  (rarely 
none). 

14.    SALICACEJE.     WILLOW  FAMILY. 

Dioecious  trees  or  shrubs,  with  flowers  in  catkins  (Ch.  XIII), 
destitute  of  floral  envelopes.  Fruit  a  1-celled  pod,  with 
numerous  seeds,  provided  with  rather  long  and  silky  down, 
by  means  of  which  they  are  transported  by  the  wind. 

I.     POPULUS,  Tourn. 

Trees  with  prominent  scaly  buds,  twigs  more  or  less  angled. 
Leaves  usually  long-petioled. 

Flowers  borne  in  long,  drooping  catkins,  which  appear 
before  the  leaves  ;  scales  of  the  catkins  irregularly  cut  toward 
the  tip.  Stamens  8-30  or  more.  Stigmas  2-4.  Capsules 
opening  early  by  2  to  4  valves. 

1.  P.  tremuloides,  Michx.    AMERICAN  ASPEN,  QUAKING  ASP.     A 

tree  20  to  60  ft.  high,  with  greenish-white  bark ;  leaves  roundish, 
heart-shaped,  abruptly  pointed,  with  small  regiilar  teeth.  Leaf- 
stalk long,  slender,  and  flattened  at  right  angles  to  the  broad 
surfaces  of  the  leaf,  causing  it  to  sway  edgewise  with  the  least  per- 
ceptible breeze.  Common  especially  N. 

2.  P.  grandidentata,  Michx.     LARGE-TOOTHED  POPLAR.     A  tree 
60  to  80  ft.  high,  with  rather  smooth  gray  bark  ;  leaves  3-5  in.  long, 
roundish  ovate  and  irregularly  sinuate-toothed;  when  young  com- 
pletely covered  with  white  silky  wool,  which  is  shed  as  soon  as  the 
leaf  matures.     The  petiole  is  somewhat  flattened,  but  not  nearly  as 
much  so  as  that  of  the  preceding  species.     Rich  woods  K. 

3.  P.  heterophylla,  L.     SWAMP  POPLAR.     Branches  only  slightly 
angled.     Leaves  ovate,  mostly  obtuse  at  the  apex,  rounded  or  sub- 
cordate  at  the  base,  serrate  with  obtuse  teeth,  densely  woolly  when 


48  FOUNDATIONS   OF  BOTANY 

young,  but  becoming  smooth  with  age  ;  petioles  cylindrical.  Pistil- 
late catkins  smooth,  erect,  or  spreading,  loosely  flowered.  Capsule 
ovoid,  usually  shorter  than  the  pedicel.  Common  in  river  swamps. 
A  large  tree  with  soft  light  wood,  which  is  often  used  in  making- 
cheap  furniture.* 

4.  P.  monilifera,  Ait.  COTTON  WOOD.  A  large  and  very  rapidly 
growing  tree,  75  to  100  or  more  feet  in  height,  often  with  a  markedly 
excurrent  trunk.  Leaves  large  and  broadly  triangular,  with  crenate- 
serrate  margins  and  long,  tapering  acute  tips  ;  petioles  long  and 
considerably  flattened.  The  numerous  pediceled  capsules  are  quite 
conspicuous  when  mature,  and  the  air  is  filled  with  the  downy 
seeds  at  the  time  when  the  capsules  open.  Common  W.,  espe- 
cially along  streams  and  planted  as  a  shade-tree. 


H.    SALIX,  Tourn. 

Shrubs  or  trees,  branches  usually  very  slender.  Buds  with 
single  scales.  Leaves  usually  long  and  narrow  ;  stipules  some- 
times leaf-like  or  often  small  and  soon  deciduous.  Bracts 
of  the  catkins  entire  ;  staminate  catkins  erect  or  drooping, 
staminate  flowers  with  2-10,  mostly  2,  distinct  or  united 
stamens.  Pistillate  catkins  usually  erect,  flowers  with  a  small 
gland  on  the  inner  side  of  the  bract,  stigmas  short,  2-lobed. 
Capsule  2-valved.* 

1.  S.  nigra,  Marsh.     BLACK  WILLOW.     Leaves  elliptical  or  nar- 
rowly lanceolate,  acute  at  each  end,  serrate,  short-petioled,  downy 
when  young  and  becoming  smooth  with  age,  2-3  in.  long ;  stipules 
persistent  or  deciduous.     Staminate  catkins  1-2  in.  long ;  the  pistil- 
late 2—4  in.  long.    Stamens  3-7,  distinct,  filaments  soft,  hairy  below. 
Capsule  twice  the  length  of  the  pedicel,  ovate,  taper-pointed,  pointed 
by  the  prominent  style.     A  small  tree  with  very  brittle  branches. 
Along  streams  and  borders  of  marshes.* 

2.  S.  babylonica,  Tourn.     WEEPING  WILLOW.     Leaves  narrowly 
lanceolate,  taper-pointed,  serrate,  slightly  downy  when  young  and 
becoming  smooth  with  age,  green  above,  pale  beneath,  often  5-7  in. 
long,  petioles  short,  glandular.     Catkins  on  short  lateral  branches. 
Stamens  2.     Style  almost  none.    Capsule  sessile,  smooth.    Introduced 
and  cultivated  for  ornament,  becoming  a  large  tree.* 

[Some  20  species  of  willow  are  found  growing  wild  in  the  north- 
eastern and  north  central  states,  but  they  are  very  hard,  even  for 
botanists,  to  identify.] 


DICOTYLEDONOUS   PLANTS  49 


15.  MYRICACE.35.     BAYBERRY  FAMILY. 

Shrubs  with  alternate,  simple,  resinous-dotted  leaves  ; 
monoecious  or  dioecious.  Flowers  in  short,  bracted  catkins, 
perianth  none.  Staminate  flowers  2-10,  stamens  inserted  on 
the  receptacle.  Pistillate  flowers  surrounded  by  2-6  scales. 
Ovary  1-celled,  style  short,  stigmas  2. 

I.    MYRICA,  L. 

Shrubs  or  small  trees  with  the  branches  clustered  at  the 
end  of  the  growth  of  the  previous  season.  Leaves  short- 
petioled,  entire,  lobed  or  toothed,  the  margin  usually  revo- 
lute,  without  stipules.  Perianth  none.  Staminate  flowers  in 
oblong  or  cylindrical  catkins,  stamens  2-10,  with  the  fila- 
ments united  below.  Pistillate  flowers  surrounded  by  a  cup 
of  2-6  scales,  ovary  solitary,  becoming  a  1-celled,  roundish 
stone-fruit  or  nut,  often  covered  with  waxy  grains.  Whole 
plant  usually  fragrant.* 

1.  M.  cerifera,  L.     WAXBERRY,  BAYBERRY.    A  spreading  shrub  or 
small  tree ;  young  branches  downy.     Leaves  lanceolate  or  oblong- 
lanceolate,  entire  or  sometimes  serrate  near  the  mostly  obtuse  apex, 
smooth  or  downy  on  the  veins  beneath,  tapering  into  a  short  petiole. 
Flowers  mostly  dioecious.     Staminate  catkins  numerous,  stamens  4. 
Pistillate  catkins  small,  bracts  slightly  3-lobed,  scales  of  the  ovary  4, 
fringed  with  hairs ;  stigmas  2.     Fruit  very  abundant,  incrusted  with 
white  wax,  |— £  in.  in  diameter,  sometimes  persistent  for  2  or  3  years. 
Common  on  wet  soils,  especially  near  the  coast.* 

2.  M.  asplenifolia,  Endl.     SWEET  FERN.     A  shrub  2  ft.  or  less  in 
height,  with  brown  twigs.     Leaves  fern-like,  linear-lanceolate,  20-30- 
lobed,  3-5  in.  long  and  very  fragrant.    Often  monoecious.    Staminate 
catkins  cylindrical.     Pistillate  catkins  globular.     Ovary  surrounded 
by  8  long,  linear,  awl-shaped,  hairy  and  glandular  scales  which  en- 
circle the  ripened  fruit.     Nut  nearly  ovoid,  smooth,  small,  but  eaten 
by  children. 

16.  JUGLANDACE^E.     WALNUT  FAMILY. 

Trees  with  alternate,  odd-pinnate  leaves  without  stipules. 
Flowers  monoecious,  the  staminate  in  long  and  drooping 
catkins,  stamens  few  or  many.  Calyx  2-6-parted.  Fertile 


50  FOUNDATIONS   OF   BOTANY 

flowers  solitary  or  in  small  clusters.  Calyx  3-5-lobed,  minute 
petals  sometimes  present.  Ovary  1-celled  or  incompletely 
2-4-celled.  Fruit  with  a  dry  husk  enclosing  a  bony  nut,* 

I.    JUGLANS,  L. 

Staminate  catkins  cylindrical,  solitary,  borne  on  wood  of 
the  previous  year,  stamens  numerous,  filaments  short,  calyx 
4-6-parted.  Pistillate  flowers  single  or  a  few  together  on  a 
short  peduncle  at  the  base  of  the  growth  of  the  season.  Calyx 
4-parted.  Petals  4,  minute,  adnate  to  the  ovary.  Styles  2, 
short,  plumose.  Fruit  large,  roundish  or  oval,  husk  fibrous- 
fleshy,  becoming  dry,  indehiscent,  nut  bony,  very  rough.* 

1.  J.  nigra,  L.     BLACK  WALNUT.     Leaflets  13-21,  ovate-lanceo- 
late, serrate,  taper-pointed,  somewhat  cordate  or  oblique  at  the  base, 
nearly   smooth    above,    downy   beneath,    petioles    minutely    downy. 
Fruit  usually  single,  roundish,  about  2  in.  in  diameter.     On  rich 
soil,  rare  near  the  coast.     One  of  the  most  valuable  of  our  native 
trees,  the  wood  being  very  durable  and  highly  prized  for  cabinet 
work.* 

2.  J.  cinerea,  L.     BUTTERNUT.     Leaflets  15-19,  ovate-lanceolate, 
taper-pointed  at  the  apex,  rounded  or  slightly  unsymmetrical  at  the 
base,  serrate,  downy  beneath ;  petioles,  branchlets,  and  fruit  clothed 
with  short,  sticky  hairs.     Fruit  often  somewhat  in  clusters,  oblong, 
large.     More  common  northward.     Wood  less  valuable  and  nut  less 
oily   than   the   black   walnut.      The    English  walnut    (J.  regia)   is 
occasionally  seen  in  cultivation.     It  has  7-11  leaflets  and  a  nearly 
smooth  nut.* 

H.    CARYA,  Nutt. 

Leaflets  serrate ;  staminate  catkins  usually  in  threes  on  a 
common  peduncle,  or  sometimes  sessile  at  the  base  of  the 
growth  of  the  season;  calyx  2-3-parted,  stamens  3-10,  fila- 
ments short.  Pistillate  flowers  2-5  in  terminal  clusters, 
calyx  4-parted,  petals  none,  styles  2  or  4,  fringed.  Fruit 
somewhat  globular,  husk  separating  more  or  less  completely 
into  4  valves.  Nut  smooth  or  angled.* 

1.  C.  olivaeformis,  Nutt.  PECAN.  A  large  tree  with  rough  gray 
bark,  young  twigs  and  leaves  downy,  nearly  smooth  when  mature. 
Leaflets  11-15,  oblong-lanceolate,  acuminate,  serrate,  scythe-shaped. 
Staminate  catkins  nearly  sessile,  5-6  in.  long.  Husk  thin  nut  oval 


DICOTYLEDONOUS   PLANTS  51 

or  oblong,  thin-shelled.     River  bottoms.     Rarely  native  east  of  the 
Mississippi  River,  but  widely  planted  for  its  fruit.* 

2.  C.  alba,  Nutt.     SHELLBARK  HICKORY.     A  large  tree  with  bark 
scaling  off  in  long  plates,  young  twigs  and  leaves  downy,  becoming 
smooth  with  age.     Leaflets  5,  the  lower  ones  oblong-lanceolate,  the 
upper  one  longer  and  obovate,  taper-pointed  at  the  apex,  narrowed 
to  the  sessile  base.     Inner  bud-scales  becoming  large  and  conspicu- 
ous.    Staminate  catkins  in  threes.     Fruit  globose,  husk  thick,  split- 
ting into  four  sections,  nut  white,   compressed,  4-angled,  pointed, 
thin-shelled.     On  rich  soil.     Metre  common  ]N".     Wood  strong  and 
elastic,  but  not  durable  when  exposed.* 

3.  C.  sulcata,  Nutt.    BIG  SHELLBARK,  KING  NUT,  BULL  NUT.    A 
tree  70-90  ft.  high,  with  shaggy  bark.     Leaflets  7  or  9,  the  terminal 
one  nearly  sessile.     Fruit  large,  ovoid  or  nearly  so,  4-grooved  toward 
the  outer  end,  the  husk  very  thick,  nut  pointed  at  each  end,  1^-2  in. 
long,  thick-shelled,  with  a  very  sweet  kernel.     Wood  hard  and  heavy. 
Common  in  rich,  damp  soil  W. 

4.  C.    amara,    Nutt.      PIGNUT,    SWAMP   HICKORY.     A    medium- 
sized  tree,  with  rather  smooth  bark.     Leaflets  7-11,  lanceolate  or 
oblong-lanceolate.     Fruit  not  large,  husk  thin,  nut  globular,  with  a 
short  point,  very  thin-shelled,  kernel  extremely  bitter.     Moist  soil, 
common  in  the  Middle  States. 


17.    BETULACE^E.     BIRCH  FAMILY. 

Trees  or  shrubs,  with  alternate,  simple,  petioled  leaves  with 
usually  deciduous  stipules.  Flowers  monoecious  in  cylindri- 
cal or  subglobose  catkins,  staminate  catkins  drooping ;  flowers 
1-3  in  the  axil  of  each  bract,  calyx  none,  or  membranous 
and  2-4-parted;  stamens  2-10,  distinct.  Pistillate  catkins 
drooping,  spreading,  or  erect  and  spike-like ;  flowers  with  or 
without  a  calyx,  ovary  solitary,  1-2-celled,  ovules  1-2  in  each 
cell.  Fruit  a  1-celled  nut  or  key.* 

I.     CARPINUS,  L. 

Trees  with  thin,  straight-veined  leaves,  which  are  folded 
in  the  bud.  Flowers  appearing  before  the  leaves  ;  staminate 
flowers  in  slender  drooping  catkins,  sessile  at  the  end  of  the 
growth  of  the  previous  season ;  stamens  3-12,  subtended  by 
a  bract,  filaments  forked,  anthers  hairy.  Pistillate  catkins 


52  FOUNDATIONS   OF   BOTANY 

spike-like,  each  pair  of  flowers  subtended  by  a  deciduous 
bract,  and  each  flower  by  a  persistent  bractlet  which  becomes 
large  and  leaf -like  in  fruit ;  ovary  2-celled,  2-ovuled ;  stigmas 
2,  thread-like.  Fruit  a  small  angular  nut.* 

1.  C.  caroliniana,  Walt.  HORNBEAM.  A  small  tree  with  smooth 
and  close  gray  bark ;  twigs  slender.  Leaves  ovate-oblong,  acute  or 
taper-pointed,  sharply  and  doubly  serrate,  the  straight  veins  terminat- 
ing in  the  larger  serrations ;  downy  when  young  and  soon  becoming 
smooth.  Staminate  catkins  1-1  £  in.  long.  Pistillate  catkins  long- 
peduncled,  8-12-flowered  ;  bractlets  becoming  nearly  1  in.  long,  cut- 
toothed,  the  middle  tooth  much  longer  than  the  others.  In  rich, 
moist  woods.  Often  known  as  "  blue  beech  "  and  "  iron-wood."  * 


H.     OSTRYA,  Micheli. 

Small  trees  with  gray  bark  and  very  hard  wood.  Leaves 
open  and  concave  in  the  bud  and  somewhat  plaited  on  the 
veins.  Staminate  flowers  on  slender,  drooping  catkins,  sessile 
at  the  end  of  the  growth  of  the  previous  season  ;  stamens 
3-12,  subtended  by  a  bract,  filaments  forked,  anthers  hairy. 
Pistillate  flowers  surrounded  by  a  tubular  bractlet  which 
becomes  large  and  bladder-like  at  maturity.  Fruit  a  small, 
pointed,  smooth  nut;  mature  catkins  hop-like.* 

0.  virginica,  Willd.  A  small  tree  with  brownish,  furrowed  bark  ; 
leaves  ovate,  acute,  doubly  serrate,  often  inequilateral  at  the  base, 
short-petioled  ;  staminate  and  fertile  catkins  2-3  in.  long.  In  rich 
woods.  Often  known  as  "iron-wood"  and  "lever-wood."* 


m.     CORYLUS,  Tourn. 

Shrubs  with  prominently  veined,  cut-toothed  leaves  which 
are  folded  lengthwise  in  the  bud.  Flowers  expanding  before 
the  leaves.  Staminate  flowers  in  slender,  drooping  catkins ; 
stamens  8,  anthers  1-celled.  Fertile  flowers  several  in  a 
cluster  or  in  very  short  catkins  at  the  ends  of  the  twigs  of 
the  season ;  ovary  incompletely  2-celled,  style  short,  stigmas 
2,  bractlets  2,  becoming  enlarged  and  enclosing  the  single 
bony  nut  at  maturity.* 

1.  C.  americana,  Walt.  HAZELNUT.  A  shrub  2-5  ft.  high,  young 
twigs  and  petioles  covered  with  brownish,  stiff  hairs.  Leaves  not 


DICOTYLEDONOUS   PLANTS  53 

very  thin,  round-cordate,  acute  or  slightly  taper-pointed,  irregularly 
toothed,  nearly  smooth  above,  downy  below.  Involucre  longer  than 
the  nut  and  partially  enclosing  it,  glandular-hairy.  Nut  subglobose, 
pointed,  edible.  On  rich  soil,  borders  of  meadows  and  fields,  and 
in  oak-openings. 

2.  C.  rostrata,  Ait.  BEAKED  HAZELNUT.  A  shrub  4-8  ft.  high. 
Young  twigs  near  ends  smooth.  Leaves  thin,  little,  if  at  all,  heart- 
shaped,  doubly  serrate  or  incised,  taper-pointed,  stipules  linear- 
lanceolate.  Involucre  completely  covering  the  nut  and  prolonged 
into  a  beak  beyond  it.  Common  N.  [The  latter  species  is  not 
nearly  as  widely  distributed  as  the  former  ;  they  cannot  be  readily 
distinguished  from  each  other  until  the  fruit  is  somewhat  mature. 
The  principal  points  of  difference  discernible  before  the  fruit  is 
nearly  mature  are  the  hairy  twigs  of  No.  1  and  the  smooth  ones  of 
No.  2,  and  the  fact  that  No.  1  has  buds  rounded  at  the  apex  and 
more  slender  and  longer  staminate  catkins,  while  No.  2  has  buds 
acute  at  the  apex  and  thicker  and  shorter  staminate  catkins.] 

IV.    BETULA,  Tourn. 

Trees  with  slender,  aromatic  twigs  and  thin,  usually  straight- 
veined  leaves.  Staminate  catkins  drooping,  flowers  usually  3 
in  the  axil  of  each  bract,  stamens  4,  short,  anthers  1-celled. 
Pistillate  catkins  erect,  flowers  2  or  3  in  the  axil  of  each  bract ; 
ovary  sessile,  2-celled,  styles  2  ;  bracts  3-lobed ;  perianth  none. 
Nut  broadly  winged.* 

1.  B.  nigra,  L.     BLACK  BIRCH,  RIVER  BIRCH.     A  medium-sized 
tree  with  reddish-brown  bark.     Leaves  rhombic-ovate,  acute  at  the 
apex,  acute  or  obtuse  at  the  base,  sharply  and  doubly  serrate,  white- 
downy  below,  becoming  smoother  with  age,  petioles  short.     Stami- 
nate catkins  2-3  in.  long.     Pistillate  catkins  1-1  £  in.  long,  peduncles 
short,  bracts  nearly  equally  3-cleft,  woolly.     River  banks,  especially 
S.  and  W.* 

2.  B.  lenta,  L.     CHERRY  BIRCH.     Leaves  ovate  or  oblong-ovate, 
acute,  heart-shaped,  finely  and  doubly  serrate,  silky  when  young  ; 
petioles  about  £  in.  long.     Staminate  catkins  clustered,  3-4  in.  long. 
Pistillate  catkins  sessile,  about  1  in.  long,  cylindrical  bracts  spread- 
ing, acute,  smooth.     River  banks,  especially  N.     A  large  tree  with 
aromatic  twigs.     The  oil  contained  in  the  bark  and  twigs  is  distilled 
and  used  as  a  substitute  for  wintergreeii.* 

3.  B.  populifolia,  Ait.     GRAY  BIRCH.     A  tall  shrub  or  slender, 
straggling  tree,  15-30  ft.  high,  seldom  growing  erect,  often  several 
trunks  springing  from  the  ground  almost  in  contact  and  slanting 
away  from  each  other.     Leaves  triangular,  with  a  long  taper  point 


54 


FOUNDATIONS   OF   BOTANY 


and  truncate  base,  unevenly  twice  serrate,  with  rather  long,  slender 
petioles,  which  allow  the  leaves  to  quiver  like  those  of  the  aspen. 
Bark  scaling  off  in  white  strips  and  layers,  but  not  in  nearly  as 
large  sheets  as  that  of  the  rarer  canoe  birch  (B.  papyri/era).  The 
commonest  birch  of  New  England. 

4.  B.  alba,  L.  EUROPEAN  WHITE  BIRCH,  CUT-LEAVED  BIRCH. 
A  tree  50  to  60  ft.  high,  often  with  drooping  branches.  Leaves 
triangular-ovate,  truncate,  rounded  or  somewhat  heart-shaped  at 
the  base,  not  strongly  taper-pointed  except  in  the  cut-leaved  form. 
Commonly  cultivated  from  Europe.  Resembles  No.  3,  but  has 
whiter  bark  and  (the  weeping  form)  much  more  slender  branches. 


V.    ALNUS,  Tourn. 

Shrubs  or  small  trees.  Leaves  petioled,  serrate.  Flower- 
buds  stalked,  appearing  the  previous  season ;  staminate  cat- 
kins racemed,  drooping,  flowers  3-6  in  the  axil  of  each  bract, 
subtended  by  1-2  bractlets,  perianth  4-parted,  stamens  4,  fila- 


FIG.  8.  —  Alntis  ghttinosa. 

A,  a  flowering  twig  ;   s,  staminate  catkins  ;  p,  pistillate  catkins  ;   B,  a  group  of 
Staminate  flowers,  enlarged ;  C,  two  pistillate  flowers,  enlarged. 


DICOTYLEDONOUS  PLANTS  55 

ments  short.  Pistillate  catkins  erect ;  flowers  2-3  in  the  axil 
of  each  bract,  perianth  replaced  by  2-4  minute  bractlets  which 
are  adherent  to  the  bract ;  ovary  2-celled,  styles  2.  Fruit  a 
winged  or  angled  nut ;  bracts  of  the  pistillate  flowers  some- 
what fleshy,  persistent,  becoming  woody  in  fruit. * 

1.  A.  serrulata,  Willd.     SMOOTH  ALDER.     A  shrub  or  small  tree 
with  smooth  bark.     Leaves  obovate,  rounded  or  obtuse  at  the  apex, 
acute  at  the  base,  sharply  and  minutely  serrate,  smooth  above,  downy 
beneath,  petioled,  stipules  oval,  deciduous.     Staminate  catkins-  2—4 
in.  long ;  fruiting  catkins  ovoid,  short-peduncled.     Fruit  ovate,  wing- 
less.    Banks  of   streams  and   borders   of   marshes,  ranging  far   S. 
Leaves  often  persistent  during  the  winter.* 

2.  A.  incana,  Willd.     SPECKLED  ALDER.     A  shrub  8-20  ft.  high. 
Leaves  broadly  oval  or  ovate,  rounded  at  the  base,  sharply  (some- 
times doubly)    serrate,  white    and   usually  downy  beneath.     Fruit 
round.     Forming  thickets  by  streams,  very  common  N. 


18.     FAGACE^E.     BEECH  FAMILY. 

Trees  or  shrubs.  Leaves  alternate,  simple,  pinnately 
veined;  stipules  deciduous.  Flowers  monoecious,  the  stami- 
nate  in  heads,  or  in  drooping,  spreading,  or  erect  catkins, 
calyx  minute,  petals  none,  stamens  4-20.  Pistillate  flowers 
solitary  or  in  small  clusters,  each  flower  subtended  by  more 
or  less  united  bracts  which  at  maturity  form  a  cup  or  bur, 
calyx  minutely  toothed,  petals  none  ;  ovary  2-7-celled,  but 
becoming  1-celled.  Fruit  a  1-seeded  nut.* 

I.    FAGUS,  Tourn. 

Trees  with  smooth,  close,  ash-gray  bark,  and  slender,  often 
horizontal  branches.  Staminate  flowers  in  long,  slender- 
peduncled,  roundish  clusters,  calyx  bell-shaped,  4-6-cleft, 
stamens  8-12,  anthers  2-celled;  pistillate  flowers  solitary  or 
more  oftdh  in  pairs,  peduncled,  surrounded  by  a  4-lobed  in- 
volucre and  numerous  linear  bracts ;  ovaries  3-celled  with  2 
ovules  in  each  cell,  but  usually  only  1  ovule  matures  in  each 
ovary ;  styles  3,  thread-shaped,  fruit  a  thin-shelled,  3-angled 
nut.* 


56  FOUNDATIONS   OF   BOTANY 

1.  F.  ferruginea,  Ait.    BEECH.    Large  trees.    Leaves  oblong-ovate, 
taper-pointed  at  the  apex,  serrate,  straight- veined,  very  white-silky 
when  young,  nearly  smooth  with  age.     Involucre  densely  covered 
with  short  recurved  spines.     Nuts  thin-shelled,  edible.     Common  on 
damp  soil  everywhere.     The  wood  is  very  hard,  tough,  and  close- 
grained,  and  is  especially  valuable  for  the  manufacture  of   small 
tools.* 

2.  F.  sylvatica,  L.     The  European  beech  is  occasionally  found 
planted  as  a  shade-tree.     The  variety  known  as  the  copper  beech 
is  most  usual,  and  is  readily  recognized  by  its  dark,  crimson-purple 
leaves. 

H.    CASTANEA,  Tourn. 

Trees  or  shrubs  with  rough,  gray,  rather  close  bark.  Leaves 
straight-veined,  undivided,  prominently  toothed.  Flowers  ap- 
pearing later  than  the  leaves.  Staminate  catkins  erect  or 
spreading,  loosely  flowered,  flowers  several  in  the  axil  of  each 
bract,  calyx  4-6-parted,  stamens  8-16.  Pistillate  flowers  at 
the  base  of  the  staminate  catkin  or  in  small  separate  clus- 
ters, usually  3  in  each  involucre  ;  ovary  4-celled,  surrounded 
by  5-12  abortive  stamens.  Fruit  a  1-celled  nut  enclosed  in 
the  greatly  enlarged  and  very  prickly  involucre.* 

1.  C.  sativa,  Mill.,  var.  americana,  Wats.     AMERICAN  CHESTNUT. 
A  large  tree,  bark  somewhat  rough,  and  splitting  into  longitudinal 
plates.     Leaves  oblong-lanceolate,  taper-pointed  at  the  apex,  usually 
acute   at  the   base,   coarsely   and   sharply   serrate   with    ascending- 
teeth,   smooth,   dark   green    above,   lighter    below ;    petioles   stout, 
short.     Staminate  catkins  erect,  6-10  in.  long.     Nuts  usually  3  in 
each  bur.     Rich  soil,  especially  N.     Rarely  found  on  soils  contain- 
ing much  lime.* 

2.  C.  pumila,  Mill.     CHINQUAPIN.    A  small  tree  or  shrub.     Leaves 
oblong,  acute  or  obtuse  at  both  ends,  serrate  with  divergent  teeth, 
dark  green  and  smooth  above,  white-woolly  below.     Nuts  solitary, 
nearly  globular.     Common  southward  in  rich  woods.* 


III.     QUERCUS,  L. 

Trees  or  shrubs  with  entire,  serrate,  or  lobed  leaves,  which 
are  of  ten .  persistent.  Staminate  flowers  in  slender  catkins, 
each  subtended  by  quickly  deciduous  bracts,  and  consisting 


DICOTYLEDONOUS  PLANTS  57 

of  3-12  stamens  enclosed  by  a  4-8-parted  perianth,  often 
containing  an  abortive  ovary.  Pistillate  flowers  solitary  or 
in  small  clusters,  each  consisting  of  a  3-celled  ovary  with 
2  ovules  in  each  cell,  though  rarely  more  than  1  ovule 
matures ;  styles  short,  erect,  or  recurved.  Pistillate  flowers 
surrounded  by  a  scaly  involucre  which  at  maturity  becomes 
a  cup  enclosing  the  base  of  the  fruit  or  sometimes  a  large 
part  of  it.  Fruit  an  ovoid  or  subglobose,  1-seeded,  thin- 
shelled  nut  (acorn). 

A.    Fruit  biennial ;    leaves   entire  or  with  bristle-pointed 
lobes.* 

1.  Q.  rubra,  L.     RED  OAK.     A  large  tree.    Leaves  oval  or  obovate, 
green  above,  pale  and  slightly  downy  beneath,  sinuses  shallow  and 
rounded,  lobes  8-12,  taper-pointed ;  petioles  long.    Cup  saucer-shaped, 
with  fine  scales  ;  acorn  ovate  or  oblong,  about  1  in.  long.     Common ; 
wood  not  valuable  ;  leaves  turning  red  after  frost  and  often  remain- 
ing on  the  tree  through  the  winter.* 

2.  Q.  coccinea,  var.  tinctoria,  Gray.     BLACK  OAK.     A  large  tree 
with  rough,  dark  brown  outer  bark  and  thick,  bright  yellow  inner 
bark;  leaves  broadly  oval,  usually  cut  more  than  halfway  to  the 
midrib,  sinuses  rounded  ;  lobes  about  7,  sharply  toothed  at  the  apex, 
smooth  above,  usually  downy  on  the  veins  beneath  ;  cup  hemispher- 
ical or  top-shaped,  with  coarse  scales,  short-peduncled,  enclosing  about 
half'  the  roundish  acorn.     Common ;    wood  not  valuable,  but  the 
inner  bark  used  for  tanning  and  dyeing.* 

3.  Q.  falcata,  Michx.     SPANISH  OAK.     A  small  or  medium-sized 
tree  with  leaves  3-5-lobed  at  the  apex,  obtuse  or  rounded  at  the 
base,  grayish-downy   beneath,  lobes   lanceolate   and   often   scythe- 
shaped,  sparingly  cut-toothed.     Cup  top-shaped,  with  coarse  scales, 
enclosing   about    half   the    nearly  round    acorn.     Common    in    diy 
woods.     Foliage  quite  variable  in  outline  and  lobing ;  bark  valu- 
able for  tanning.* 

4.  Q.  nigra,  L.     BLACK-JACK  OAK.     A  small  tree  ;  leaves  obovate, 
usually  with  three  rounded  lobes  at  the  apex,  the  lobes  bristle-pointed, 
rounded,  or  slightly  cordate  at  the  base,  rusty-pubescent  beneath, 
shining   above,    coriaceous,    short-petioled;    cup   top-shaped,    short- 
peduncled,  with   coarse    and  truncate  scales,  enclosing  about   one- 
third   of   the   oblong-ovate  acorn.     An   almost   worthless   tree,  its 
presence  indicating  a  thin  and  sterile  soil.* 

5.  Q.  Phellos,  L.     WILLOW  OAK.     A  tree  of  medium  size,  leaves 
lanceolate  or  elliptical,  scurfy  when   young   and  becoming  smooth 
with  age  ;  very  short-petioled  ;  cup  shallow,  sessile ;  acorn  subglobose. 
Wet  soil ;  often  planted  for  shade.* 


58  FOUNDATIONS   OF   BOTANY 

B.    Fruit  annual ;    leaves  not  bristle-tipped,  though  often 
nmcronate. 

6.  Q.  alba,  L.     WHITE  OAK.     A  large  tree  with  light  gray  bark. 
Leaves  obovate-oblong,  3-9-lobed,  lobes  rounded  and  mostly  entire, 
bright  green  above,  paler  below,  short-petioled.     Cup  hemispherical, 
scales  rough,  woolly  when  young,  but  becoming  smooth  with  age  ; 
acorn  oblong-ovate,  about  1  in.  long.     Common  in  damp  soil ;  wood 
strong  and  durable ;  one  of  the  most  valuable  timber  trees.* 

7.  Q.  stellata,  Wang.     POST  OAK.     A  tree  of  medium  size  with 
rough  gray  bark.    Leaves  broadly  obovate,  deeply  lyrate-pinnatified 
into  5-7  rounded,  divergent  lobes,   upper  lobes  much  the  longer, 
smooth  above,  yellowish-downy  beneath,  petioles  about  1  in.  long. 
Cup  hemispherical,  nearly  sessile ;  acorn  ovoid,  2-3  times  as  long  as 
the  cup.     On  dry  soil  ;  wood  hard  and  valuable. 

8.  Q.  macrocarpa,  Michx.     BUR  OAK.     A  medium-sized  to  very 
large  tree,  with  roughish  gray  bark.     Leaves  obovate  or  oblong, 
lyrately  and  deeply   sinuate-lobed,  smooth   above,  pale   or   downy 
beneath.     Cup  very  deep  and  thick,  abundantly  fringed  about  the 
margin,  |  in.  to  2  in.  in  diameter.     Acorn,  half  or  more  [sometimes 
entirely]  enclosed  by  the  cup.     Reaches  its  full  size  only  on  rich 
bottom  lands  S.  and  W.,  where  it  becomes  one  of  the  finest  timber 
oaks.     Wood  very  hard  and  heavy. 

9.  Q.  lyrata,  Walt.     SWAMP  OAK.     A  large  tree  with  gray  or 
reddish    bark.      Leaves    obovate-oblong,    deeply    pinnatifid,    lobes 
narrow,   often  toothed,  thin,  smooth  above,  white,  densely  woolly 
beneath.     Cup  round-ovate,  scales  cuspidate,  enclosing  nearly  the 
whole  of  the  depressed-globose  acorn.     On  wet  soil ;  wood  strong 
and  very  durable.* 

10.  Q.  prinus,  L.     SWAMP  CHESTNUT  OAK.     A  large  tree  with 
brown,  ridged  bark.     Leaves  oblong  or  oblong-lanceolate,  rather  ob- 
tuse, crenately  toothed,  minutely  downy  beneath,  petioles  slender, 
about  1   in.  long.      Cup  hemispherical,  peduncles  longer  than  the 
petioles,  scales  acute,  tubercular,   appressed  ;   acorn  oblong,  acute, 
1    in.   or  less  in  length,  edible.     Common  on  low  ground.     Wood 
strong  and  valuable.* 

11.  Q.-  Muhlenbergii,   Engelm.      YELLOW    CHESTNUT    OAK.      A 
tree  of  medium  or  large  size  with  gray  bark.     Leaves  oblong  or 
oblanceolate,  usually  acute  at  the  apex  and  obtuse  or  rounded  at  the 
base,  coarsely  and  evenly  toothed ;  veins  straight,  impressed  above 
and  prominent  beneath  ;  petioles  slender.    Cup  hemispherical,  sessile 
or  short-peduncled,  with  flat  scales,  ^  in.  broad,  enclosing  about  half 
the  ovoid  acorn,  which  is  f-f  in.  long.     Common  on  dry  soil,  wood 
close-grained,  durable,  and  valuable. 

12.  Q.  virginiana,  Mill.     LIVE  OAK.     A  large  tree  with  rough 


DICOTYLEDONOUS   PLANTS 


59 


gray  or  brown  bark  and  a  low,  spreading  top.  Leaves  leathery, 
evergreen,  oblong  or  oblanceolate,  often  somewhat  3-lobed  on  young 
trees,  margin  rolled  under,  dark  green  and  shining  above,  pale 
below  ;  petioles  short,  stout.  Fruit  often  in  short  racemes,  cup  top- 
shaped,  scales  closely  appressed,  hoary,  peduncles  4—1  in.  long ;  acorn 
from  subglobose  to  oblong,  the  longer  form  occurring  on  the  younger 
trees.  On  low  ground  near  the  coast ;  wood  very  hard  and  durable  ; 
valued  for  shipbuilding.* 


19.    ULMACEJE.     ELM  FAMILY. 

Trees  or  shrubs  with  watery  juice,  alternate,  simple,  petio- 
late,  serrate,  stipulate  leaves,  which  are  usually  2-ranked  ; 
and  small,  perfect,  or  somewhat  monoecious,  apetalous  flowers. 
Calyx  of  3-9  sepals  which  are  distinct  or  partly  united, 
stamens  as  many  as  the  sepals  and 
opposite  them.  Ovary  1  —  2 -celled, 
styles  2,  spreading.  Fruit  a  key, 
nut,  or  stone  fruit.* 


D 


FIG.  9.  —  Ulmus  campestris. 
A,  a  flowering  twig  ;  B,  a  flower  ;  C,  longitudinal  section  of  a  flower  ;  Z>,  a  fruit. 


I.    ULMUS,  L. 

Trees  with  straight-veined,  unsymmetrical,  doubly  serrate 
leaves  ;  stipules  early  deciduous.  Flowers  perfect,  calyx 
bell-shaped,  4-9-cleft.  Stamens  slender,  protruding.  Ovary 
compressed,  styles  2,  spreading.  Fruit  membranaceous,  flat, 
winged  on  the  edge.* 


60  FOUNDATIONS   OF   BOTANY 

1.  U.  americana,  L.     WHITE  ELM.     A  large  tree  with  gray  bark, 
drooping  branches,  and  smooth  or  slightly  downy  twigs.     Leaves 
oval  or    obovate,   abruptly  taper-pointed    at   the  apex,   obtuse  and 
oblique  at  the  base,  slightly  rough  above,  soft  downy  or  soon  smooth 
beneath.     Flowers  in    close    fascicles,    peduncles    slender,    smooth. 
Fruit   oval   or   obovate,  with  2  sharp  teeth   bending  toward  each 
other  at  the  apex,  wing  reticulate-veined,  downy  on  the    margin. 
In   moist,  rich    soil.     A    widely   planted    ornamental    tree;    wood 
strong  but  warping  badly,  and  not  durable  when  exposed.* 

2.  U.  alata,  Michx.     WINGED  ELM.     A  small  tree  with  branches 
corky-winged.     Leaves  small,  ovate-lanceolate,  acute,  sharply  serrate, 
base  nearly  equal-sided,  rough  above,  downy  beneath,  nearly  sessile. 
Flowers  in  small  clusters.     Fruit  oblong,  downy  on  the  sides,  ciliate 
on  the  edges.     On  rich  soil.     Occasionally  producing  a  second  set  of 
flowers  and  fruit  from  September  to  November.* 

3.  U.  fulva,  Michx.     SLIPPERY  ELM.     A  tree   of  medium  size 
with   rough    downy   twigs,    and   rusty,    densely   woolly  bud-scales. 
Leaves  large,  thick,  very  rough  above,   downy  beneath,  ovate  or 
obovate,  taper-pointed  at  the  apex,  unsymmetrical,  obtuse  or  some- 
what cordate  at  the  base,   coarsely  and  doubly  serrate,  calyx-lobes 
and  pedicels  downy.     Fruit  broadly  oval,  downy  over  the  seed,  the 
wing  smooth.     Inner  bark  very  fragrant  when  dried,  and  a  popular 
domestic  remedy.* 

H.     CELTIS,  Tourn. 

Trees  or  shrubs  with  entire  or  serrate,  petioled  leaves. 
Flowers  greenish,  axillary,  on  wood  of  the  same  season,  the 
staminate  in  small  clusters,  the  fertile  single  or  2-3  together.* 

1.  C.  occidentalis,  L.      HACKBERRY.      A  large  or  medium-sized 
tree  having  much  the  appearance  of  an  elm,  bark  dark  and  rough. 
Leaves  ovate,  taper-pointed  at  the  apex,  abruptly  obtuse  and  inequi- 
lateral at  the  base,  sharply  serrate,  often  3-nerved  from  the  base, 
smooth  above,  usually  somewThat  downy  below.     Fruit  a  small,  dark 
purple  stone  fruit.     On  rich  soil. 

2.  C.  mississippiensis,  Bosc.     SOUTHERN    HACKBERRY.     A  tree 
usually  smaller  than  the    preceding,  bark  gray,  often  very  warty. 
Leaves  broadly  lanceolate  or  ovate,  long  taper-pointed  at  the  apex, 
obtuse  or  sometimes  heart-shaped  at  the  base,  entire  or  with  very 
few  serratures,  smooth  on  both  sides,  3-nerved.     Fruit  a  purplish- 
black,  globose  stone  fruit.* 


DICOTYLEDONOUS   PLANTS  61 


20.    HORACES.     MULBERRY  FAMILY. 

Trees,  shrubs,  or  herbs,  usually  with  milky  juice,  alternate 
leaves,  large  deciduous  stipules  and  small  mono3cious  or  dioe- 
cious  flowers  crowded  in  spikes,  heads  or  racemes,  or  enclosed 
in  a  fleshy  receptacle.  Staminate  flowers  with  a  3-4-lobed 
calyx,  stamens  3-4,  inserted  on  the  base  of  the  calyx,  fila- 
ments usually  inflexed  in  the  bud,  straightening  at  maturity. 
Pistillate  flowers  3-5-sepalous  ;  ovary  1-2-celled,  1-2-ovuled  ; 
styles  2,  receptacle  and  perianth  often  fleshy  at  maturity.* 

I.    MORUS,  Tourn. 

Trees  or  shrubs  with  milky  juice,  rounded  leaves,  and 
monoecious  flowers  in  axillary  spikes.  Staminate  flowers 
with  a  4-parted  perianth,  and  4  stamens  inflexed  in  the  bud. 
Pistillate  flowers  with  a  4-parted  perianth  which  becomes 
fleshy  in  the  multiple  fruit,  the  pulpy  part  of  which  consists 
of  the  thickened  calyx,  bracts  and  so  on  of  many  flowers  ; 
ovary  sessile,  stigmas  2,  linear,  spreading  ;  the  fleshy  perianth 
enclosing  the  ovary  at  maturity.* 

1.  M.  rubra,  L.     RED  MULBERRY.     A  small  tree.     Leaves  cor- 
date-ovate, often  3-5-lobed  on  vigorous  shoots,  taper-pointed  at  the 
apex,  serrate,  rough  above,  white,  densely  woolly  beneath.     Mature 
fruiting  spikes  oblong,  drooping,  dark  red  or  purple,  edible.    On  rich 
soil.     Wood  very  durable,  bearing  exposure  to  the  weather. 

2.  M.    alba,    L.     WHITE    MULBERRY.     A    small   tree.      Leaves 
ovate,  heart-shaped,  acute  at  the  apex,  rounded  and  often  oblique  at 
the  base,  serrate  or  sometimes  lobed.     Smooth  and  shining  on  both 
sides.     Mature  fruit  light  red  or  white.     Introduced  and  common 
about  old  dwellings.* 

II.    MACLURA,  Nutt. 

A  small  tree  with  milky  juice.  Leaves  alternate,  petioled, 
spines  axillary.  Flowers  dioecious.  Staminate  flowers  in 
short  axillary  racemes  ;  calyx  4-parted  ;  stamens  4,  inflexed 
in  the  bud.  Pistillate  flowers  in  axillary,  peduncled,  capitate 
clusters  ;  calyx  4-parted,  ovaTy  sessile,  style  long  ;  calyces 
becoming  thickened  and  fleshy  in  fruit  and  aggregated  into  a 
large,  dense,  globular  head.* 


62  FOUNDATIONS   OF   BOTANY 

1.  M.  aurantiaca,  Nutt.  OSAGE  ORANGE.  A  small  tree  with  ridged, 
yellowish-brown  bark.  Leaves  minutely  downy  when  young,  becom- 
ing smooth  and  shining  with  age,  ovate  or  ovate-oblong,  taper- 
pointed  at  the  apex,  obtuse  or  subcordate  at  the  base,  entire,  petioled. 
Staminate  racemes  about  1  in.  long.  Pistillate  flower  clusters  about 
1  in.  in  diameter.  Fruit  yellowish,  tubercled,  3-4  in.  in  diameter. 
In  rich  soil.  Native  in  Texas  and  extensively  planted  for  hedges. 
Wood  very  durable  when  exposed  to  the  weather,  and  therefore  used 
for  fence  posts.  As  the  wood  does  not  swell  or  shrink  with  changes 
in  its  moisture,  it  is  highly  valued  for  wheel  hubs,  etc.* 

III.    BROUSSONETIA,  L'Her. 

Small  trees  with  milky  juice.  Leaves  alternate,  petioled ; 
flowers  dioecious.  Staminate  in  cylindrical  spikes,  with  a 
4-cleft  calyx,  4  stamens,  and  a  rudimentary  ovary.  Pistil- 
late flowers  in  capitate  clusters.  Calyx  3-4-toothed.  Ovary 
stalked,  style  2-cleft,  fruit  in  a  globular  head.* 

1.  B.  papyrifera,  Vent.  PAPER  MULBERRY.  A  round-topped  tree 
with  yellowish-brown  bark.  Leaves  cordate,  often  irregularly  2-3- 
lobed,  serrate,  rough  above,  downy  beneath,  long-petioled.  Stami- 
nate spikelets  peduncled,  2-3  in.  long.  Pistillate  heads  stout,  pedun- 
cled,  about  1  in.  in  diameter.  Introduced  from  Asia  and  very 
common  S.  about  old  dooryards.* 

IV.     CANNABIS,  Tourn. 

Coarse  herbs  with  very  tough,  fibrous  bark.  Leaves  usu- 
ally opposite,  palmately  compound.  Flowers  small,  dioecious, 
greenish,  the  Staminate  ones  in  compound  racemes  or  panicles, 
the  pistillate  ones  in  spikes.  Calyx  of  the  starninate  flowers 
of  5  sepals,  that  of  the  pistillate  flowers  of  1  large  sepal 
which  covers  the  ovary  and  the  akene. 

1.  C.  sativa,  L.  COMMON  HEMP.  An  erect  plant,  4-8  ft.  high. 
Leaves  large,  petioled,  of  5-7  lanceolate,  irregularly  serrate  or 
toothed  leaflets.  Cultivated  from  Europe,  S.  and  W.,  for  its  fiber, 
and  sometimes  runs  wild  along  roadsides  in  rich  soil. 


21.    URTICACE^.     XETTLE  FAMILY. 

Herbs  with  watery  juice,  stem  and  leaves  often  clothed 
with  stinging  hairs.     Leaves  undivided,  stipulate.     Flowers 


DICOTYLEDONOUS  PLANTS  63 

small,  greenish,  imperfect,  apetalous  in  axillary  clusters. 
Calyx  of  the  staminate  flowers  4-5-parted  or  4-5-sepalous  ; 
stamens  as  many  as  the  sepals  and  opposite  them,  filaments 
inflexed  in  the  bud  and  straightening  at  maturity,  anthers 
2-celled.  Calyx  of  pistillate  flowers  2-4-sepalous ;  ovary 
sessile,  1-celled,  stigma  simple  or  tufted.  Fruit  an  akene 
commonly  enclosed  in  the  dry,  persistent  calyx.* 

URTICA,  Tourn. 

Annual  or  perennial  herbs.  Leaves  with  stinging  hairs, 
opposite,  petioled,  several-nerved,  dentate,  or  incised,  stipulate. 
Flowers  monoecious  or  dioecious.  Calyx  of  the  staminate 
flowers  4-parted  ;  stamens  4,  inserted  around  a  rudimentary 
ovary.  Pistillate  flowers  with  4  unequal  sepals,  the  inner 
ones  dilated  in  fruit ;  akenes  smooth,  compressed.* 

1.  U.  urens,  L.  SMALL  NETTLE.  Annual ;  stem  stout,  4-angled, 
hairy,  12-18  in.  tall,  with  few  stinging  hairs  ;  branches  slender. 
Leaves  elliptical  or  ovate,  serrate  or  incised,  3-5-nerved,  acute  or 
obtuse  at  the  ends,  thin,  hairy  ;  petioles  often  as  long  as  the  blades  ; 
stipules  short.  Flower  clusters  axillary,  in  pairs,  loose,  mostly 
shorter  than  the  petioles.  On  damp  soil  in  waste  places.* 

22.   LORANTHACEJE.     MISTLETOE  FAMILY. 

Parasitic  shrubs  or  herbs,  leaves  opposite,  leathery,  with- 
out stipules.  Flowers  monoecious  or  dioecious,  clustered  or 
solitary ;  perianth  of  both  calyx  and  corolla,  or  of  a  calyx 
only,  or  sometimes  wanting  ;  calyx-tube  adnate  to  the  ovary, 
sepals  2-8.  Stamens  as  many  as  the  sepals,  and  opposite 
them ;  ovary  1-celled,  ovule  1.  Fruit  a  berry.* 

PHORADENDRON,  Nutt. 

Evergreen,  shrubby  plants,  parasitic  on  trees;  branches 
greenish,  jointed,  and  very  brittle.  Leaves  leathery.  Flowers 
dioecious,  in  short  jointed  spikes.  Staminate  flowers  globular, 
calyx  2-4-lobed,  stamens  sessile  at  the  base  of  the  lobes, 


64  FOUNDATIONS   OF  BOTANY 

anthers  transversely  2-celled.  Pistillate  flowers  with  the 
calyx-tube  adnate  to  the  ovary,  stigma  sessile,  berry 
1-seedecL* 

1.  P.  flavescens,  Nutt.  AMERICAN  MISTLETOE.  Very  round,  bushy  ; 
branches  very  brittle  at  the  joints,  opposite  or  whorled,  6  in.  to  2  ft. 
long.  Leaves  flat,  leathery,  or  somewhat  fleshy,  nearly  veinless, 
obovate,  entire,  with  short  petioles.  Flowering  spikes  solitary  or 
2-3  together  in  the  axils  of  the  leaves.  Berry  roundish,  white, 
glutinous.  Parasitic  on  many  deciduous  trees.* 


23.    SANTALACE-3L.     SANDALWOOD  FAMILY. 

Herbs,  shrubs,  or  trees  with  entire  leaves.  Flowers  usually 
small.  Calyx  4-5-cleft,  its  tube  adnate  to  the  ovary.  Corolla 
wanting.  Stamens  as  many  as  the  calyx-lobes  and  opposite 
them,  inserted  on  the  margin  of  a  fleshy  disk.  Style  1.  Ovary 
1-celled,  with  2-4  ovules  borne  at  the  top  of  a  free  central 
placenta.  Fruit  1-seeded. 

COMANDRA,  Nutt. 

Low,  smooth  perennials  with  herbaceous  stems,  rather 
woody  below,  often  parasitic.  Leaves  alternate  and  nearly 
sessile.  Flowers  nearly  white,  in  small  umbel-like  clusters, 
perfect.  Calyx  bell-shaped  at  first.  Stamens  borne  on  a 
5-lobed  disk  which  surrounds  the  pistil,  anthers  connected 
by  a  tuft  of  hairs  to  the  calyx-lobes. 

1.  C.  umbellata,  Nutt.  BASTARD  TOAD-FLAX.  Plant  8-10  in. 
high,  with  very  leafy  stems.  Roots  attached  to  the  roots  of  trees, 
from  which  they  draw  nourishment.  Leaves  oblong  or  oblanceolate, 
pale,  nearly  1  in.  long.  Umbel-like  clusters  about  3-flowered,  longer 
than  the  leaves.  Rocky,  dry  woods. 

24.    ARISTOLOCHIACEJE.     DUTCHMAN'S  PIPE  FAMILY. 

Herbaceous  plants,  stemless  or  with  twining  and  leafy 
stems.  Leaves  alternate,  without  stipules,  petioled,  mostly 
roundish  or  kidney-shaped.  Flowers  axillary,  solitary  or 
clustered,  perfect,  regular  or  irregular.  Calyx  tubular,  3  or 


DICOTYLEDONOUS  PLANTS  65 

6  lobed,  usually  colored.   Petals  none.    Stamens  6-12,  inserted 
on  the  ovary.     Pistils  1,  ovary  mostly  6-celled,  many-seeded.* 

I.    ASARUM,  Tourn. 

Perennial,  stemless,  aromatic  herbs,  with  slender,  branch- 
ing rootstocks.  Leaves  long-petioled,  from  kidney-shaped  to 
halberd-shaped.  Flowers  axillary,  peduncled.  Calyx  regular, 
3-lobed,  withering-persistent.  Stamens  12,  the  filaments  par- 
tially united  with  the  style  and  usually  prolonged  beyond  the 
anthers.  Ovary  6-celled  with  parietal  placentse,  many-seeded. 
Mature  capsule  roundish,  often  somewhat  fleshy.* 

1.  A.  canadense,  L.     WILD  GINGER.     Plant  soft,  hairy.    Leaves 
2,  large,  kidney-shaped,  on  long  petioles,  with  the  flower  borne  on  a 
short  peduncle  between  them.     Flower  greenish  outside,  brownish- 
purple  inside.     Calyx-tube  wholly  adnate  to  the  ovary,  calyx-lobes 
taper-pointed,  widely  spreading,  reflexed  at  the  tip.     Rich,  shady 
woods,  common  N. 

2.  A.  virginicum,  L.    VIRGINIA  ASARUM.    Leaves  evergreen,  1-3 
to  each  plant,  smooth,  mottled,  round-cordate,  entire,  2—3  in.  long 
and  broad;  petioles  smooth  or  downy  along  one  side,  3-7  in.  long. 
Flowers  nearly  sessile,  greenish  without,  dull  purple  within,  |-|  in. 
long,  tube  inflated  below,  narrow  at  the  throat,  lobes  spreading. 
Rich,  shady  woods.* 

IL    ARISTOLOCHIA,  Tourn. 

Erect  or  twining  perennial  herbs  or  woody  vines.  Leaves 
alternate,  heart-shaped  at  the  base,  palmately  nerved,  petioled, 
entire.  Flowers  irregular,  solitary,  or  in  small  clusters. 
Calyx  more  or  less  adnate  to  the  ovary,  tubular,  irregular. 
Stamens  mostly  6,  sessile,  adnate  to  the  angled  and  fleshy 
3-6-lobed  or  angled  stigma.  Capsule  naked,  6-valved,  seeds 
very  numerous.* 

1.  A.   Sipho,   L'Her.      DUTCHMAN'S    PIPE,  PIPE  VINE.     A  tall 
climber.     Leaves  dark   green,  smooth,  round-kidney-shaped,  some- 
times 1  ft.  wide.    Peduncles  1-flqwered,  with  a  single  clasping  bract. 
Calyx  H  in.  long,  bent  into  the  shape  of  a  pipe,  its  border  abruptly 
spreading,  brownish-purple.     Rich  woods,  often  cultivated. 

2.  A.  tomentosa,  Sims.    DUTCHMAN'S  PIPE.    Stem  woody,  climb- 
ing high,  branches  and  leaves  densely  woolly.    Leaves  heart-shaped, 
prominently  veined,  3-5  in.  long   and  broad.      Flowers    axillary, 


66  FOUNDATIONS   OF   BOTANY 

mostly  solitary,  on  slender  peduncles.  Calyx  bent  in  the  shape  of 
a  pipe,  yellowish-green  with  a  dark  purple  throat,  limb  unequally 
3-lobed,  rugose,  reflexed.  Anthers  in  pairs  below  the  3  spreading 
lobes  of  the  stigma.  Capsule  oblong.  Stems  sometimes  30  ft.  long. 
Rich  woods  S.* 


25.   POLYGONACE^).     BUCKWHEAT  FAMILY. 

Herbs  with  alternate,  entire  leaves  and  usually  with  sheath- 
ing stipules  above  the  swollen  joints  of  the  stem.  Flowers 
apetalous,  generally  perfect,  with  a  3-6-cleft  calyx,  generally 
colored  and  persistent.  Fruit  a  compressed  or  3-angled  akene, 
enclosed  in  the  calyx.  Seeds  with  endosperm,  which  does  not 
generally  enclose  the  embryo.  Stamens  4-12,  on  the  base  of 
the  calyx. 

I.    RUMEX,  L. 

Coarse  herbs,  many  of  them  troublesome  weeds.  Flowers 
small,  usually  green  or  greenish,  generally  in  whorls  borne  in 
panicled  racemes.  Calyx  of  6  nearly  distinct  sepals,  the  3 
inner  larger  and  more  petal-like  than  the  3  outer,  and  one 
or  more  of  them  usually  with  a  little  knob  or  tubercle  on  its 
back.  Stamens  6.  Styles  3.  Stigmas  short,  fringed.  Fruit 
a  3-angled  akene,  closely  covered  by  the  3  inner  calyx-lobes, 
enlarged  and  known  as  valves. 

1.  R.  Acetosella,  L.     SHEEP  SORREL.    Erect  annual  or  perennial 
herbs  with  creeping  rootstocks.     Stem  simple  or  branched,  smooth. 
Leaves  petioled,  narrowly  halberd-shaped,  usually  widest  above  the 
middle,  the  apex  acute  or   obtuse,  upper  stem-leaves  often  nearly 
linear  and  not  lobed.    Flowers  dioecious,  small,  in  terminal,  naked, 
panicled,  interrupted  racemes.     Calyx  greenish ;  the  pistillate  pani- 
cles becoming  reddish.     Fruit  less  than  T^  in.  long,  granular,  longer 
than  the  calyx.     A  common  introduced  weed,  in  dry  fields  and  on 
sour  soils.     Foliage  very  acid.*  • 

2.  R.  verticillatus,   L.     SWAMP   DOCK.      Perennial,    stem    stout, 
smooth,   erect   or   ascending,    3-5 '  ft.    tall.     Lower   leaves   oblong, 
obtuse  at  the  apex  and   usually  heart-shaped   at   the  base,  long- 
petioled,  often   12-18  in.    long,   upper  leaves    narrower  and   often 
acute  at  both  ends.     Flowers  perfect  or  somewhat  monoecious,  in 
dense  whorls,  pedicels  slender,  i-|  in.    long,  tapering  downward, 


DICOTYLEDONOUS   PLANTS  67 

reflexed  at  maturity.  Calyx  green,  the  valves  broadly  triangular, 
abruptly  pointed,  reticulated,  a  distinct  long  and  narrow  tubercle  on 
the  back  of  each.  Swamps  and  wet  ground.* 

3.  R.  crispus,  L.  YELLOW"  DOCK.  Stout,  smooth,  3-4  ft.  high. 
Leaves  lanceolate,  margins  very  wavy,  acute,  the  lower  more  or  less 
heart-shaped.  Root  long,  tapering  gradually  downward,  yellow, 
very  tough.  Flowers  in  whorls  crowded  in  long,  straight,  slender 
racemes.  Valves  roundish  heart-shaped,  mostly  tubercled.  A  very 
hardy  weed,  introduced  from  Europe. 


II.    POLYGONUM,  L. 

Annual  or  perennial,  terrestrial  or  aquatic  herbs,  with 
enlarged  joints  and  simple,  alternate,  entire  leaves ;  the 
sheathing  stipules  often  cut  or  fringed.  Flowers  perfect, 
usually  white  or  rose-colored,  each  flower  or  cluster  subtended 
by  a  membranaceous  bract,  similar  to  the  stipules  of  the 
leaves.  Calyx  mostly  5-parted,  the  divisions  petal-like,  erect 
and  persistent.  Stamens  3-9.  Styles  2-3-parted.  Fruit 
lens-shaped  or  3-angled.* 

1.  P.  aviculare,  L.     KNOT-GRASS.     Annual  or  perennial.     Stem 
prostrate  or  ascending,  diffuse,  smooth,  6-24  in.  long.    Leaves  small, 
lanceolate  or  linear-oblong,  obtuse,  nearly 

or  quite  sessile.  Stipules  thin  and  dry,  2-3- 
cleft  or  cut.  Flower-clusters  axillary,  1-5- 
flowered,  flowers  inconspicuous,  nearly  ses- 
sile. Calyx  greenish-white,  5-parted,  the 
lobes  with  white  or  colored  borders.  Stamens 
5-8.  Style  3-parted ;  akene  3-angled,  not 
shining.  A  common  weed  in  dooryards  and  A  B 

where  the  ground  is  trampled.*  FIG.  10.—  Buckwheat. 

2.  P.     DumetOrum,    L.        FALSE     BUCK-     A,  flower,  longitudinal    sec- 
WHEAT.    Perennial ;  stems  slender,  twining,       tion  '•>  B> fruit  (both  some- 
branched,    2-10   ft.    long.      Leaves   ovate,       ^ -larged>- 
taper-pointed,   heart-shaped  to    halberd-shaped   at   the   base,    long- 
petioled.     Stipules  cylindrical,  truncate.     Flowers  in  axillary,  more 
or  less  compound  and  leafy  racemes.      Calyx  greenish-white,   the 
outer  lobes  winged  and  forming  a  margin  on  the  pedicel.     Stamens 
8.    Stigmas  3  ;  akene  3-angled,  black,  smooth,  and  shining.    Margins 
of  fields  and  thickets.* 


68  FOUNDATIONS   OF   BOTANY 


26.    CHENOPODIACE^.     GOOSEFOOT  FAMILY. 

Herbs  or  shrubs.  Leaves  simple,  alternate,  without  sti- 
pules. Flowers  small,  regular,  either  perfect  or  more  or 
less  monoecious  or  dioecious.  Calyx  free  from  the  ovary. 
Corolla  wanting.  Stamens  usually  5,  opposite  the  sepals. 
Styles  or  stigmas  generally  2.  Fruit  with  1  seed,  usually 
enclosed  in  a  small,  bladdery  sac,  sometimes  an  akene. 

I.    SPINACIA,  Tourn. 

Herbs.  Flowers  dioecious,  in  close  axillary  clusters.  Stami- 
nate  flowers  3-5-sepaled,  with  4  or  5  projecting  stamens. 
Pistillate  flowers  with  a  tubular  2-toothed  or  4-toothed  calyx. 

1.  S.  oleracea,  Mill.  SPINACH.  A  soft  annual  or  biennial  herb. 
Leaves  triangular,  ovate,  or  halberd-shaped,  petioled.  Cultivated 
from  Asia  as  a  pot-herb. 

n.    CHENOPODIUM,  Tourn. 

Annual  or  perennial  herbs.  Stems  erect  or  spreading. 
Leaves  alternate,  usually  white-mealy.  Flowers  small,  green- 


FiG.  \\.-Chenopodium. 
A,  flower  ;  B,  fruit. 


ish,  in  panicled  spikes.  Calyx  3-5-parted,  the  lobes  often 
slightly  fleshy  and  keeled.  Stamens  5  ;  filaments  thread- 
shaped.  Styles  2-3,  distinct  or  united  at  the  base.  Seed 
lens-shaped.* 


DICOTYLEDONOUS   PLANTS  69 

1.  C.  hybridum,  L.    MAPLE-LEAVED  GOOSEFOOT.     A  tall  annual 
herb  2-4  ft.  high.     Leaves  2-6  in.  long,  thin,  bright  green,  long, 
taper-pointed,  with  several  angled  lobes  on  each  side,  terminating  in 
pointed  teeth.     Flower-clusters   rather  large,  consisting  of  loosely 
paiiicled  racemes.     A  rather  common  weed. 

2.  C.  Botrys,  L.     JERUSALEM  OAK.     A  low  spreading  plant  cov- 
ered with  sticky  down.     Leaves  with  slender  petioles,  oblong,  sin- 
uately  lobed  or   the  lobes  pinnate.     Flowers   in  loose,  diverging, 
leafless   racemes.     The  whole   plant   is   sweet-scented.     Introduced 
from  Europe  and.  naturalized  in  gardens  and  along  roadsides. 

27.    PHYTOLACCACEJE.     POKEWEED  FAMILY. 

Plants  with  alternate  entire  leaves.  Flowers  perfect,  5- 
parted,  with  the  characters  of  the  Goosefoot  Family,  but  the 
ovary  generally  consisting  of  several  carpels,  which  unite  to 
form  a  berry. 

PHYTOLACCA,  Tourn. 

Perennial  herbs.  Stems  tall,  branching.  Leaves  large, 
entire.  Flowers  small,  in  terminal  racemes,  pedicels  bracted. 
Calyx  of  4-5  nearly  equal,  persistent  sepals.  Stamens  5-15, 
inserted  at  the  base  of  the  calyx.  Styles  5-12,  recurved  at 
the  apex.  Fruit  a  depressed-globose,  juicy  berry.* 

1.  P.  decandra,  L.  POKEWEED.  Stems  erect,  smooth,  branched 
above,  usually  dark  purple,  4-7  ft.  tall ;  root  large,  fleshy,  poisonous. 
Leaves  ovate-lanceolate,  smooth,  acute,  long-petioled.  Racemes  pedun- 
cled,  many-flowered,  opposite  the  leaves,  flowers  white,  becoming 
purplish.  Stamens  10,  shorter  than  the  sepals.  Styles  10,  car- 
pels 10;  fruit  a  dark  purple  berry.  A  weed  on  waste  ground. 
The  young  branches  are  often  eaten  like  asparagus,  and  the  root, 
known  as  "  garget  root,"  is  used  in  medicine.* 

28.   AIZOACE^:.     ICE-PLANT  FAMILY. 

Mostly  fleshy  plants,  mainly  natives  of  Africa.  Flowers 
often  large  and  showy.  Stamens  often  doubled  and  some  of 
them  petal-like.  Ovary  2-many-celled. 

[Our  only  very  common  genus  belongs  to  a  subfamily 
which  has  little  resemblance  to  the  fleshy  "  ice-plants,"  found 
in  some  gardens,  which  best  represent  the  family  as  a  whole.] 


70  FOUNDATIONS   OF   BOTANY 


MOLLUGO,  L. 

Low  branching  annuals.  Sepals  5,  greenish  outside,  white 
inside.  Corolla  wanting.  Stamens  5,  alternate  with  the 
sepals,  or  3,  alternate  with  the  cells  of  the  ovary.  Capsule 
3-celled,  many-seeded. 

1.  M.  verticillata,  L.  CARPET-WEED.  Stems  branching  and 
forming  radiating  patches.  Leaves  clustered  in  apparent  whorls  at 
the  joints  of  the  stem,  spatulate.  Flowers  in  little  sessile  umbels  at 
the  joints.  Stamens  commonly  3.  A  troublesome  weed  in  sandy 
soil  and  common  on  sandy  beaches  and  river  banks. 


29.   PORTULACACE^E.     PURSLANE  FAMILY. 

Generally  herbs.  Leaves  opposite  or  alternate,  entire ; 
stipules  dry  and  membranaceous.  Sepals  2.  Petals  4  or 
more,  distinct  or  united  below.  Stamens  4  or  more,  free  or 
adnate  to  the  petals.  Ovary  usually  free,  1-celled;  style 
simple  or  3-cleft  ;  ovules  2-many.  Capsule  opening  trans- 
versely with  a  lid,  or  2-3-valved. 


I.    CLAYTONIA,  Gronov. 

Perennial ;  stem  simple,  smooth,  erect,  4-10  in.  high. 
Leaves  2,  opposite,  smooth,  succulent.  Flowers  in  a  terminal 
raceme.  Sepals  2,  ovate,  persistent.  Petals  5,  sometimes 
coherent  at  the  base.  Stamens  5,  inserted  on  the  base  of 
the  petals.  Style  3-cleft,  ovary  1-celled,  3-6-seeded. 

1.  C.  virginica,  L.     SPRING  BEAUTY.     Stem  simple,  erect  from  a 
deep,  tuberous  root.     The  2  stem-leaves  narrowly  elliptical,  3-6  in. 
long,  smooth,  fleshy;  basal  leaves  occasionally  produced.     Flowers 
on  short  pedicels.     Petals  white  or  pink,  with  darker  veins,  ^-f  in. 

\       long,  notched.    Capsule  shorter  than  the  persistent  sepals.    Common 
\  in  rich  woods.* 

2.  C.  caroliniana,  Michx.     NORTHERN  SPRING  BEAUTY.     Flowers 
fewer,  smaller,  and  whiter  than  No.  1,  fragrant.     Leaves  1-2  in. 
long,  ovate-lanceolate  or  spatulate,  pretty  distinctly  petioled.     Moist 
woods,  especially  N. 


DICOTYLEDONOUS   PLANTS  71 


II.     PORTULACA,  Tourn. 

Annual ;  stems  low,  diffuse,  and  spreading,  fleshy.  Leaves 
entire,  mostly  alternate.  Flowers  terminal.  Sepals  2f  united 
at  the  base  and  coherent  with  the  ovary.  Petals  usually  5,  in- 
serted on  the  calyx,  quickly  withering.  Stamens  8-20,  inserted 
on  the  calyx.  Style  3-8-parted.  Capsule  globose,  opening 
by  the  upper  portion  coming  off  like  a  lid,  1-celled,  many- 
seeded.* 

1.  P.  oleracea,  L.     PURSLANE.     Stems  prostrate,  diffuse,  fleshy. 
Leaves  alternate,  flat,  obovate,  or  wedge-shaped.     Flowers  solitary, 
sessile,  opening  in  bright  sunshine   in  the  morning,   and  usually 
withering  before  noon.     Sepals  broad,  acute.     Petals  yellow.     Sta- 
mens 10-12.     Capsule  very-many-seeded,  seeds  small,  wrinkled.     A 
common  garden  weed.* 

2.  P.  grandiflora,  Hook.     GARDEN   PORTULACA.      Stems   fleshy, 
erect,  or  ascending,  densely  hairy  or  nearly  smooth,  3-6  in.  long. 
Leaves  alternate,  cylindrical,  fleshy,  £-1  in.  long.     Flowers  1-2  in. 
wide,  white,  yellow,  or  red,  showy,  opening  only  in  sunlight.     Com- 
mon in  cultivation  and  often  growing  spontaneously.* 


30.    CARYOPHYLLACEJE.     PINK  FAMILY. 

Herbs  sometimes  woody  below,  with  thickened  nodes. 
Leaves  opposite,  entire  ;  stipules  small  and  dry  or  none. 
Sepals  4-5.  Petals  4-5  (rarely  0),  usually  hypogynous.  Sta- 
mens usually  8-10,  hypogynous  or  perigynous.  Styles  2-5 
(rarely  1).  Ovules  2-many.  Fruit  a  capsule. 

A. 

Sepals  distinct  or  nearly  so.     Petals  (if  any}  without  claws.     Capsule 

several-many-seeded. 

Styles  usually  3.     Capsule  ovoid.  Stellaria;  I. 

Styles  5  or  4.      Capsule  cylindrical.  Cerastium,  II. 

B. 

Sepals  united  into  an  urn-shaped  tube.     Petals  none.     Fruit  1-seeded. 

Scleranthus,  III. 


72  FOUNDATIONS   OF   BOTANY 

C. 

Sepals   more    or   less    united.      Petals  with    claws.      Capsule    several- 
many-seeded. 

(a)  Calyx  without  bracts,  its  lobes  long  and  leaf-like. 

Agrostemma,  IV. 
(&)  Calyx  without  bracts,  lobes  not  leaf-like.     Styles  3  or  4. 

Silene,  V. 

(c)  Calyx  without  bracts,  lobes  not  leaf -like.   Styles  5  (rarely  4). 

Lychnis,  VI. 
(d}  Calyx  with  little  bracts  at  the  base.     Styles  2. 

Dianthus,  VII. 

I.    STELLARIA,  L.     Chickweed. 

Slender,  usually  smooth  herbs.  Flowers  small,  white,  soli- 
tary, or  in  forking  cymes.  Sepals  5  (rarely  4).  Petals  5 
(rarely  4),  2-cleft  or  divided.  Stamens  10  (rarely  8,  5,  or  3), 
maturing  in  2  sets.  Styles  3  (rarely  4  or  5),  opposite  the  same 
number  of  petals ;  ovary  1-celled,  many-ovuled.  Capsule 
short,  splitting  into  as  many  valves  as  there  are  styles. 

1.  S.    media,    Cyrill.      COMMON    CHICKWEED.     Stem  prostrate, 
6-18  in.  long,  with  a  line  or  two  of  hairs  along  it.     Leaves  ovate, 
taper-pointed,  the  lower  petioled,  the  upper  sessile.     Petals  shorter 
than  the  sepals,  sometimes  wanting.     An  annual  weed,  introduced 
from  Europe,  common  in  damp,  shady  places  N. 

2.  S.    longifolia,    Muhl.      LONG-LEAVED    STITCHWORT.       Stem 
slender,  usually  erect,  8-18  in.  high,  often  sharply  4-angled.    Leaves 
linear  or  nearly  so,  spreading.      Flower-clusters  peduncled,  many- 
flowered,  the  pedicels  spreading.     Petals  2-parted,  at  length  longer 
than  the  calyx.     Perennial  in  meadows  and  grassy  thickets,  espe- 
cially N. 

H.     CERASTIUM,  L. 

-  Annual  or  perennial.  Stems  diffuse,  usually  downy  ;  leaves 
opposite.  Flowers  white,  peduncled,  in  terminal,  regularly 
forking  cymes.  Sepals  4-5.  Petals  4-5,  notched  or  2-cleft. 
Stamens  10.  Styles  5  or  less.  Capsule  cylindrical,  1-celled, 
many-seeded.* 

1.  C.  vulgatum,  L.  MOUSE-EAR  CHICKWEED.  Annual  or  some- 
times perennial.  Stems  diffuse,  tufted,  clammy-downy,  6-12  in. 


DICOTYLEDONOUS   PLANTS  73 

high.  Lower  leaves  spatulate,  the  upper  oblong,  acute,  or  obtuse  ; 
bracts  thin  and  dry.  Flowers  in  loose  cymes,  pedicels  becoming 
much  longer  than  the  calyx.  Sepals  lanceolate,  acute,  about  as  long 
as  the  2-cleft  petals.  Slender  capsule  becoming  twice  as  long  as  the 
calyx  aiid-curved  upward.  A  common  garden  weed.* 

HI.     SCLERANTHUS,  L. 

Low  tufted  herbs.  Leaves  opposite,  clasping,  awl-shaped, 
sharp-pointed.  Flowers  very  small  and  greenish.  Calyx- 
tube  funnel-shaped  or  urn-shaped,  hardening  into  an  envelope 
for  the  fruit ;  calyx-lobes  4-5,  short,  erect.  Petals  none. 
Stamens  1,  2,  5,  or  10,  inserted  on  the  throat  of  the  calyx. 
Styles  2,  thread-like.  Fruit  1-seeded,  never  opening. 

1.  S.  anmms,  L.  KNAWEL.  A  much-branched  annual  weed, 
2-8  in.  high.  Stem  and  leaves  pale  green  ;  the  leaves  \  to  \  in. 
long,  rather  prickly  pointed.  Flowers  solitary  in  the  lower  axils 
and  somewhat  clustered  above.  Calyx-teeth  with  narrow  whitish 
margins.  Introduced  from  Europe,  common  in  sandy  roads  and 
waste  ground  E. 

IV.    AGROSTEMMA. 

Annual  ;  stem  pubescent,  branching  above.  Leaves  linear- 
lanceolate  or  linear,  pubescent,  sessile.  Flowers  showy,  on 
long  and  naked  peduncles  in  terminal  corymbs.  Calyx  tubu- 
lar, the  tube  oblong,  10-ribbed,  lobes  elongated,  leaf -like, 
deciduous.  Petals  5,  shorter  than  the  calyx  lobes,  entire. 
Stamens  10.  Styles  5,  capsules  1-celled.* 

1.  A.  Githago,  L.  CORN  COCKLE.  Stem  erect,  rather  slender,  1-3 
ft.  tall,  gray,  with  long,  appressed  hairs.  Leaves  linear-lanceolate, 
acuminate,  erect,  2-4  in.  long.  Petals  obovate,  notched,  purple. 
Capsule  5-toothed,  many-seeded  ;  seeds  black.  An  introduced  weed, 
common  in  grain  fields.* 

V.    SILENE,  L. 

Annual  or  perennial  herbs.  Stems  erect  or  decumbent  and 
diffuse.  Leaves  often  connate  or  whorled.  Flowers  clustered 
or  solitary,  usually  pink  or  white.  Calyx  tubular,  more  or 
less  inflated,  5-toothed,  10-nerved,  bractless.  Petals  5,  long- 
clawed,  and  with  the  ten  stamens  inserted  at  the  base  of  the 
ovary.  Styles  3,  ovary  1-celled  or  3-celled  at  the  base,  open- 
ing by  6  teeth,  many-seeded.  Seeds  usually  roughened.* 


74  FOUNDATIONS   OF   BOTANY 

1.  S.  Cucubalus,  Wibel.     SNAPPERS,    RATTLEBOX.     A  perennial 
branched  herb  about  1  ft.  high.     Leaves  opposite,  smooth,  ovate,  or 
ovate-lanceolate.       Calyx    thin   and   bladdery,    beautifully   veined. 
Petals  white,  2-cleft.     Capsule  nearly  globular.     In  fields  and  along 
roadsides,  especially  eastward.     Introduced  from  Europe. 

2.  S.  pennsylvanica,  Michx.     WILD  PINK.     A  perennial  with  low- 
clustered  stems  (4-8  in.).     Root-leaves  wedge-shaped  or  spatulate, 
those    of    the   stem  lanceolate.      Flowers    medium-sized,  clustered. 
Petals  wedge-shaped,  notched,  pink,  with  a  crown  at  the  throat  of 
the  corolla.     Gravelly  soil  E. 

3.  S.  virginica,  L.     FIRE  PINK.     A  slender  perennial  with  erect 
stem,  1-2  ft.  high.     Root-leaves  spatulate,  the  upper  leaves  oblong- 
lanceolate.     Flowers  few,  peduncled,  large  and  showy,  bright  crim- 
son.    Corolla  crowned,  petals  deeply  2-cleft.     Woods. 

4.  S.  Armeria,  L.    CATCHFLY,  NONE-SO-PRETTY.    A  smooth,  erect 
annual  or  biennial,  6-15  in.  high.     Several  nodes  of  the  stem  are 
usually  covered  for  part  of  their  length  with  a  sticky  substance. 
Leaves  very  smooth,  with  a  bloom  beneath,  lanceolate  or  oblong- 
lanceolate,  clasping.      Flowers   showy,  dark   pink,  nearly  £   in.  in 
diameter,  in  flat-topped  clusters.     Calyx  club-shaped.     Petals  some- 
what notched.     Cultivated  from  Europe  and  introduced. 

5.  S.  antirrhina,  L.     SLEEPY  CATCHFLY.     Stem  smooth,  slender, 
8—30  in.  high,  sticky  in  spots.     Leaves  lanceolate  or  linear.    Flowers 
rather  few  and  small,  panicled.      Calyx  ovoid.      Petals  inversely 
heart-shaped,  pink,  opening  only  for  a  short  time  in  sunshine.     Dry 
waste  ground. 

6.  S.  noctiflora,  L.    NIGHT-FLOWERING  CATCHFLY.    A  tall,  coarse 
annual  or  biennial  weed,  covered  with  sticky  hairs.     Lower  leaves 
spatulate,  the  upper  ones   lanceolate  and  pointed.     Flowers  large, 
white,  opening  at  night  or  in  cloudy  weather.    Calyx-teeth  very  long 
and  awl-shaped.     Petals  2-parted.    In  fields  and  gardens,  introduced 
from  Europe. 

VI.    LYCHNIS,  L. 

Plants  with  nearly  the  same  characteristics  as  Silene,  but 
usually  with  5  styles. 

1.  L.  chalcedonica,  L.     SCARLET  LYCHNIS,  LONDON  PRIDE.      A 
tall,  hairy  perennial,  (about  2  ft.).     Leaves  lance-ovate,  somewhat 
clasping.       Flower-cluster    flat-topped    and    very    dense.      Flowers 
bright   scarlet,   not  very  large.      Petals  2-lobed.      Common  in  old 
gardens  ;  from  Russia. 

2.  L.    coronaria,    Lam.      MULLEIN   PINK.      A  forking   perennial 
plant,  2  ft.  high,  covered  with  white,  cottony  down.     Root-leaves 
very  wavy,  spatulate  ;  stem-leaves  ovate-lanceolate,  wavy,  clasping. 


DICOTYLEDONOUS  PLANTS  75 

Peduncles  long,  1-flowered.  Flowers  about  1^  in.  broad,  deep  crim- 
son. Calyx-tube  very  strongly  5-ribbed,  with  5  smaller  ones  between  ; 
calyx-teeth  short  and  slender.  Petals  somewhat  notched.  Culti- 
vated in  old  gardens ;  from  Italy. 

VII.    DIANTHUS,  L. 

Tufted,  mostly  perennial  herbs,  often  shrubby  at  the  base. 
Leaves  narrow  and  grass-like.  Flowers  solitary  or  variously 
clustered.  Calyx  tubular,  5-toothed,  with  overlapping  bracts 
at  the  base.  Petals  5,  with  long  claws.  Stamens  10,  matur- 
ing 5  at  a  time.  Styles  2  ;  ovary  1-celled.  Capsule  cylindrical, 
4-valved  at  the  top. 

1.  D.  Armeria,  L.     DEPTFOKD  PINK.     Rather  erect,  annual,  with 
stiff  stems  1-2  ft.  high.    Leaves  very  dark  green,  linear,  1-2  in.  long, 
the  lower  obtuse,  the  upper  acute.     Flowers  loosely  clustered,  small, 
dark   pink.       Calyx-tube  £-f  in.   long,  nearly   cylindrical.     Petals 
narrow,  speckled  with  very  small   whitish  dots.      In  sandy   fields 
eastward,  introduced  from  Europe;  sometimes  cultivated. 

2.  D.  barbatus,  L.     SWEET  WILLIAM.     Perennial,  often  in  large 
clumps.    Stems  erect,  branching  above,  smooth,  1-2  ft.  tall.    Leaves 
lanceolate,  2—3    in.   long,   acute.      Flowers  crimson-pink,  white  or 
variegated,  in  terminal  clusters,  bracts  linear,  as  long  as  the  calyx. 
Common  about  old  gardens ;  from  Europe.* 

3.  D.  plumarius,  L.    COMMON  PINK,  GRASS  PINK.    Leaves  grass- 
like,  with  a  whitish  bloom.     Petals  white,  pink,  or  variegated,  with 
the  limb  fringed.      Flowers  solitary,  fragrant.      Hardy  perennials, 
cultivated  from  Europe. 

4.  D.  Caryophyllus,  L.      CARNATION,  CLOVE  PINK.     Much  like 
the  preceding  species,  but  with  larger  fragrant  flowers ;  the  broad 
petals  merely  crenate.     Hothouse  perennials  (some  hardy  varieties), 
cultivated  from  Europe. 

31.   NYMPILSEACEJE.     WATER-LILY  FAMILY. 

Perennial  aquatic  herbs.  Leaves  usually  floating,  often 
shield-shaped.  Flowers  borne  on  naked  scapes.  Floral  en- 
velopes and  stamens  all  hypogynous  or  else  adnate  to  a  fleshy 
disk  that  encloses  the  carpels.  Sepals  3-6.  Petals  3-5  or 
often  very  numerous.  Stamens  many.  Carpels  3  or  more, 
free,  in  a  single  circle  or  united  with  the  disk.  Fruit  a  berry 
or  a  group  of  separate  carpels. 


76  FOUNDATIONS   OF  BOTANY 


I.    NELUMBO,  Toura. 

Eootstock  large  and  stout.  Leaves  round,  shield-shaped, 
often  raised  above  the  water.  Flowers  large,  raised  above 
water  at  first,  but  often  submerged  after  blooming.  Sepals 
and  petals  hypogynous,  numerous,  the  inner  sepals  and  outer 
petals  not  distinguishable  from  each  other.  Stamens  many, 
hypogynous.  Pistils  several,  1-ovuled,  borne  in  pits  in  the 
flattish  upper  surface  of  a  top-shaped  receptacle,  which,  en- 
larges greatly  in  fruit. 

1.  N.   lutea,   Pers.     AMERICAN   LOTUS.     WATER   CHINQUAPIN. 

Rootstock  often  3-4  in.  in  diameter,  horizontal.  Leaves  1^-2^  ft. 
broad,  prominently  ribbed,  with  much  bloom  above,  often  downy 
beneath.  Petioles  and  peduncles  stout.  Flowers  pale  yellow,  5-9 
in.  broad.  Sepals  and  petals  falling  quickly.  Fruit  top-shaped, 
3-4  in.  in  diameter  ;  the  seeds  ^  in.  in  diameter.  In  ponds  and 
slow-running  streams  W.,  introduced  from  the  Southwest.* 

II.    NYMPH^A,  Toura. 

Rootstock  horizontal,  creeping  extensively.  Leaves  float- 
ing, entire,  shield-shaped  or  heart-shaped.  Flowers  showy. 
Sepals  4,  green  without,  white  within.  Petals  many,  white, 
becoming  smaller  towards  the  center.  Stamens  many,  the 
outer  with  broad  and  the  inner  with  linear  filaments.  Ovary 
many-celled,  stigmas  shield-shaped  and  radiating.  Fruit  berry- 
like,  many-seeded.* 

1.  N.  odorata,  Ait.  WHITE  WATER-LILY.  Rootstock  large, 
branched  but  little.  Leaves  floating,  entire,  the  notch  narrow,  and 
basal  lobes  acute,  green  and  smooth  above,  purple  and  downy 
beneath.  Petioles  and  peduncles  slender.  Flowers  white,  very 
fragrant,  opening  in  the  morning,  3-5  in.  broad.  Fruit  globose, 
seeds  enclosed  in  a  membranaceous  sac.  In  ponds  and  still  water.* 

m.    NUPHAR,  Smith. 

Rootstock  horizontal,  thick,  cylindrical.  Leaves  heart- 
shaped,  floating  or  erect.  Flowers  yellow.  Sepals  4-6, 
green  on  the  outside,  obovate,  concave.  Petals  many,  hypogy- 
nous, the  inner  ones  becoming  small  and  stamen-like.  Sta- 
mens many,  hypogynous.  Ovary  cylindrical,  many-celled, 
stigma  disk-shaped.  Fruit  ovoid.* 


DICOTYLEDONOUS   PLANTS  77 

1.  N.  advena.  YELLOW  POND  LILY,  Cow  LILY,  SPATTERDOCK. 
Leaves  oval  or  orbicular,  rather  thick,  often  downy  beneath.  Flowers 
bright  yellow,  2-3  in.  in  diameter,  depressed-globular.  Sepals  6. 
Petals  thick  and  fleshy,  truncate.  Stamens  in  several  rows,  anthers 
nearly  as  long  as  the  filaments.  In  slow  streams  and  still  water.* 

32.    RANUNCULACEJE.     BUTTERCUP  FAMILY. 

Herbs,  rarely  shrubs,  usually  with  biting  or  bitter  juice. 
Leaves  radical  or  alternate  (in  Clematis  opposite  ;  stem-leaves 
or  involucre  whorled  in  anemone)  ;  stipules  none  or  adnate  to 
the  petiole.  Floral  organs  all  distinct  and  unconnected. 
Sepals  5  or  more  (rarely  2-4),  falling  early,  often  petal-like. 
Petals  none,  or  5  or  more  (rarely  3).  Stamens  many.  Carpels 
many,  1-celled ;  stigmas  simple ;  ovules  1  or  more.  Fruit 
composed  of  1-seeded  akenes  or  many-seeded  follicles.  Seeds 
small 

A. 

Flowers  irregular. 

With  a  spur.  Delphinium,  VII. 

With  a  hood.  Aconitum,  VIII. 

B. 

Flowers  regular. 

1.  Petals  present  (in  c  not  very  unlike  the  stamens). 

(a)  Petals  very  large  and  showy.  Paeon  ia,  I. 

(&)  Petals  small,  tubular  at  the  tip.  Coptis,  IV. 

(c)  Petals  narrow,  spatulate,  on  slender  claws.  Actsea,  V. 
(e?)  Petals  prolonged  backward  into  spurs.  Aquilegia,  VI. 
(e)  Petals  flat,  with  a  little  scale  at  the  base,  inside. 

Ranunculus,  XIII. 

2.  Petals  none,  or  very  small  and  stamen-like. 

(a)  Sepals  yellow.  Calfha,  II. 

(b)  Sepals  greenish  or  white,  falling  as  the  flower  opens. 

Thalictrum,  XIV. 

(c)  Sepals  white  or  colored,  involucre  sepal-like.  Hepatica,  X. 

(d)  Sepals  4.     Plants  climbing.  Clematis,  XII. 


78  FOUNDATIONS  OF  BOTANY 

(e)  Sepals  5,  white.     Flowers  axillary  and  terminal.     Pods 
2-several-seeded.  Isopyrum,  II  I. 

(/)  Sepals  white  or  colored.     Plants  not  climbing.     Akenes 
more  or  less  tailed  with  the  styles  in  fruit. 

Anemone,  IX. 

(g)  Sepals    5-10,    white.      Flowers   in    an    umbel.      Roots 
tuberous.  Anemonella,  XI. 

I.    P^EONIA,  L. 

Perennial ;  from  thick,  fleshy  roots  ;  stems  shrubby  or  her- 
baceous. Leaves  much  divided.  Flowers  terminal,  large  and 
showy.  Sepals  5,  leaf-like  and  persistent.  Petals  5  or  more. 
Pistils  3-5  ;  ovaries  surrounded  by  a  disk.* 

1.  P.  officinalis,  L.  GARDEN  P^ONY.  Herbaceous;  flowering- 
stems  1-2  ft.  high.  Leaves  ample ;  leaflets  lance-ovate,  cut  or 
incised,  smooth.  Flowers  double,  white  or  red.  Follicles  2,  erect, 
many-seeded.  Common  in  gardens.* 

H.    CALTHA,  L. 

Smooth  perennials  with  large,  roundish  leaves.  Sepals 
petal-like,  5-9.  Petals  none.  Pistils  5-10,  each  consisting 
of  a  1-celled  ovary  with  a  nearly  sessile  stigma.  Fruit  a 
many-seeded  follicle. 

1.  C.  palustris.  MARSH  MARIGOLD,  COWSLIPS,  MEADOW  BUTTER- 
CUP (both  the  latter  unsuitable  names,  but  in  common  use).  Stem 
hollow,  smooth,  ascending ;  leaves  smooth,  roundish  and  heart- 
shaped,  or  kidney-shaped,  with  crenate,  dentate,  or  nearly  entire 
margins;  the  broad  oval  sepals  bright  yellow.  Swamps  or  wet 
ground. 

m.    ISOPYRUM,  L. 

Small,  smooth  herbs.  Leaves  2-3  times  compound,  in 
threes  j  the  leaflets  2-3-lobed.  Flowers  peduncled,  white. 
Sepals  5,  petal-like,  soon  falling.  Petals  wanting  (in  our 
species).  Stamens  10-40.  Pistils  3-6  or  more. 

1.  I.  biternatum,  Torr.  and  Gr.  A  delicate,  erect  plant,  with  alter- 
nate branches,  looking  much  like  Anemonella,  with  clustered  steins 
from  perennial  tuberous  roots.  Damp  woods. 


DICOTYLEDONOUS   PLANTS  79 


IV.    COPTIS,  Salisb. 

Low,  smooth  perennials  with  3-divided  root-leaves.  Flowers 
small,  white,  on  scapes.  Sepals  5-7,  petal-like,  soon  fall- 
ing. Petals  5-7,  small,  club-shaped,  tubular  at  the  apex. 
Stamens  15-25.  Pistils  3-7,  stalked.  Pods  thin  and  dry, 
4-8-seeded. 

1.  C.  trifolia,  Salisb.  GOLD  THREAD.  A  pretty,  delicate  plant, 
with  slender,  1-flowered  scapes,  from  long,  bright-yellow,  thread-like 
rootstocks,  which  are  bitter  and  somewhat  medicinal.  Leaves  later 
than  the  flowers,  each  of  3  wedge-shaped  leaflets,  which  finally 
become  shining  and  evergreen.  Damp,  cold  woods  and  bogs. 

v.   ACT;EA,  L. 

Perennial  ;  stem  simple.  Leaves  2-3,  compound  in  threes. 
Leaflets  ovate,  sharply  cut  or  toothed.  Flowers  white,  in  a 
short  and  thick  terminal  raceme.  Sepals  4-5,  soon  decidu- 
ous. Petals  4-10,  small.  Pistil  single  ;  stigma  2-lobed. 
Fruit  a  many-seeded  berry.* 

1.  A.  alba,  Bigel.    BANEBERRY.    Stem  erect,  smooth  or  nearly  so, 
18-24  in.  high.    Leaves  large  and  spreading ;  leaflets  thin.    Racemes 
very  broad.     Petals  slender,  truncate.     Pedicels  red,  thickened  in 
fruiting;  berries  white.     In  rich  woods,  more  common  S.* 

2.  A.  spicata,  var.  rubra,  Ait.     RED  BANEBERRY.      Stem  about 
2  ft.  high.    Raceme  ovoid  or  hemispherical.    Petals  acute.    Pedicels 
slender.     Berries  usually  red,  sometimes  white,  ovoid.     Common  N". 

VI.    AQUILEGIA,  Tourn. 

Perennials  with  leaves  twice  or  thrice  palmately  compound, 
the  divisions  in  threes. 

Sepals  5,  petal-like,  all  similar.  Petals  5,  all  similar,  each 
consisting  of  an  expanded  portion,  prolonged  backward  into 
a  hollow  spur,  the  whole  much  longer  than  the  calyx.  Pistils 
5,  forming  many-seeded  pods. 

1.  A.  canadensis,  L.     WILD  COLUMBINE.     Flowers  scarlet  with- 
out, yellow  within,  nodding ;  spurs  rather  long. 

2.  A.  vulgaris,  L.     GARDEN  COLUMBINE.     Flowers  often  double 
and  white,  blue,  or  purple.     Spurs  shorter  and  more  hooked.     Cul- 
tivated from  Europe,  and  sometimes  become  wild. 


80  FOUNDATIONS   OF  BOTANY 


VII.    DELPHINIUM,  Tourn. 

Annual  or  perennial  herbs  ;  stem  erect,  simple,  or  branched. 
Leaves  alternate,  petioled,  palmately  divided.  Flowers  in  ter- 
minal racemes  or  panicles,  showy.  Sepals  5,  colored,  irregu- 
lar, the  upper  one  prolonged  into  a  spur.  Petals  4,  unequal, 
the  two  upper  ones  with  long  spurs  which  are  enclosed  in  the 
spur  of  the  upper  sepal,  the  other  two  short-stalked.  Pistils 
1-5  ;  ovaries  many-seeded.* 

.  1.  D.  tricorne,  Michx.  DWARF  LARKSPUR.  Perennial.  Stem 
simple,  from  a  tuberous  root,  usually  low  (^  to  1  ft.  high),  but  some- 
times 2  ft.  high.  Leaves  deeply  5-parted,  the  divisions  irregularly 
3-5-cleft.  Racemes  few-flowered,  loose.  Flowers  blue,  sometimes 
white.  Pods  diverging.  Southward. 

2.  D.  azureum,  Michx.  BLUE  LARKSPUR.  Perennial.  Stem 
usually  simple,  slender,  downy,  1-2  ft.  high.  Leaves  2-3  in.  wide, 
3-5-parted,  the  divisions  cleft  into  3-5  narrow,  toothed,  or  entire 
lobes.  Flowers  in  a  strict,  many-flowered,  terminal  raceme,  showy, 
blue  or  whitish.  Spur  ascending,  curved  ;  lower  petals  bearded,  2- 
cleft.  Pods  erect.  On  rich  or  rocky  soil  in  open  places.  Northward.* 

VHI.    ACONITUM,  L. 

Erect,  perennial  herbs.  Leaves  alternate,  palmately  lobed 
or  cut.  Flowers  irregular,  in  panicles  or  racemes.  Sepals  5, 
the  back  one  large,  arched,  and  hooded,  the  front  one  the 
narrowest.  Petals  2-5,  small,  the  2  back  ones  clawed  and 
covered  by  the  hood  of  the  sepals  ;  3  lateral  ones  small 
or  wanting.  Follicles  3-5.  Seeds  many,  wrinkled. 

1.  A.  Napellus,  L.  MONKSHOOD.  An  erect,  poisonous  plant, 
1-2  ft.  high.  Raceme  simple  and  densely  flowered.  Flowers  dark 
blue.  Cultivated  from  Europe. 

IX.    ANEMONE,  Tourn. 

Perennial  herbs,  usually  with  radical  leaves,  and  2  or  3 
opposite  or  whorled  stem-leaves,  constituting  an  involucre 
some  distance  below  the  flower  or  flower-cluster.  Sepals  few 
or  numerous,  colored  and  petal-like.  Petals  usually  wanting. 
Akenes  pointed,  or  with  long,  feathery  tails. 

1.  A.    patens,   var.  nuttalliana,   Gray.     PASQUE   FLOWER.     Low 

plants,  1  in.  to  1  ft.  high,  clothed  with  long,  silky  hairs.     Leaves 


DICOTYLEDONOUS   PLANTS  81 

divided  in  threes.  Flower  single,  large,  showy,  pale-purplish,  borne 
on  a  peduncle  developed  before  the  leaves.  Carpels  many,  with  long, 
hairy  styles,  which  in  fruit  form  tails  2  in.  long.  Prairies  and 
bluffs,  N.  W. 

2.  A.    caroliniana,   Walt.      CAROLINA   ANEMONE.     Stem  simple, 
from  a  roundish  tuber,  slightly  downy,  6-12    in.   high,  bearing  a 
single  flower  about  1  in.  broad.    Root-leaves  2-3,  long-petioled,  com- 
pound  in   threes,    the   divisions   cut  or  lobed ;  stem-leaves  sessile, 
compound   in   threes,  the  divisions   wedge-shaped.     Sepals  12-20, 
white;  head  of   fruit  becoming  oblong;  akenes  woolly.     In  open 
woods  W.* 

3.  A.  cylindrica.      LONG-FRUITED   ANEMONE.      Plants   about   2 
ft.  high,  branching,  with  an  involucre  of  long-petioled,  divided  and 
cleft  leaves,  from  within  which  spring  several  long,  naked  peduncles. 
Flowers  greenish-white.     Sepals  obtuse.     Head  of  fruit  cylindrical, 
composed  of  very  many  densely  woolly  akenes.     Dry  woods  and 
prairies. 

4.  A.  virginiana,  L.     Plant  hairy,  2-3  ft.  high.     Peduncles  6-12 
in.  long,  sometimes  forking,  the  first  ones  naked,  the  later  ones  with 
a  little  2-leaved  involucre  at  the  middle.     Leaves  of  the  involucre  3, 
each  3-parted,  the  divisions  ovate-lanceolate,  pointed.     Sepals  acute. 
Head  of  fruit  ovoid.     Woods  and  meadows. 

5.  A.  quinquefolia,  L.    WIND-FLOWER,  WOOD  ANEMONE.  ,  Stem 
simple,  from   a  thread-like  rootstock ;    involucre  of  3  leaves,  each 
petioled,  and  of  3  leaflets,  which  are  cut,  toothed,  or  parted.    Pedun- 
cle 1-flowered.     Sepals  4-7,  white,  often  tinged  with  purple  outside. 
Carpels  15  or  20.     This  species  is  very  nearly  related  to,  but  now 
regarded  as  distinct  from,  the  European  A.  nemorosa. 


X.    HEP ATICA,  Dill. 

Involucre  of  3  small,  simple  leaves,  so  close  to  the  flower  as 
to  look  like  a  calyx.  Leaves  all  radical,  3-lobed,  heart-shaped, 
thick,  and  evergreen,  purplish-red  beneath.  Flowers  single, 
on  rather  slender  hairy  scapes. 

1.  H.  triloba,  Chaix.     ROUND-LOBED  HEPATICA.     Lobes  of  the 
leaves  obtuse  or   rounded  ;  those  of  the   involucre   obtuse  ;  sepals 
6-12,  varying  from  blue  to  white. 

2.  H.  acutiloba,  DC.     SHARP-LOBED  HEPATICA.     Closely  similar 
to  the  former,  except  for  the  acute  lobes  of  the  leaves  and  tips  of 
the  involucre. 

[Both  species  have  many  local  names,  such  as  Liverleaf ,  Liverwort, 
Noble  Liverwort,  Spring  Beauty.] 


82  FOUNDATIONS   OF  BOTANY 


XI.    ANEMONELLA,  Spach. 

Small,  perennial  herbs.  Leaves  compound,  smooth,  those 
from  the  root  long-petioled,  those  of  the  stem  sessile.  Flowers 
in  a  terminal  umbel,  slender-pediceled.  Sepals  petal-like. 
Petals  none.  Pistils  4-15  ;  stigmas  sessile,  truncate.* 

1.  A.  thalictroides,  Spach.  RUE  ANEMONE.  Stem  slender,  6-10  in. 
high,  from  a  cluster  of  tuberous  roots.  Radical  leaves  long-petioled, 
twice  compound  in  threes,  leaflets  oval,  heart-shaped,  3-5-lobed. 
Stem-leaves  2-3  compound  in  threes  whorled,  the  long-stalked  leaf- 
lets veiny,  forming  an  involucre  of  6-9  apparently  simple  leaves. 
Flowers  3-6  in  an  umbel,  £-£  in.  wide ;  sepals  6-10,  white.  In  rich 
woods.* 

XH.    CLEMATIS. 

Perennial  herbs  or  slightly  woody  vines,  usually  climbing 
by  the  leaf-stalks.  Leaves  opposite,  simple,  or  compound. 
Sepals  4,  petal-like.  Petals  very  small  or  wanting.  Pistils 
numerous,-  tipped  by  the  persistent  styles  which  often  become 
long  and  plumose  in  fruit.* 

1.  C.    crispa,    L.      MARSH  CLEMATIS.     Stem   climbing,  a   little 
woody  below,  slightly  downy  above,  3-5  ft.  high.     Leaves  pinnately 
compound;    leaflets  5-7,  varying  from   lanceolate   to   ovate,   thin, 
entire,  or  3-5-lobed.     Flowers  showy,  perfect,  solitary,  on  long,  axil- 
lary peduncles.     Sepals  lanceolate,  taper-pointed,  thick,  wavy  on  the 
margins,  twice  the  length  of  the  stamens,  light  bluish-purple,  1-1^ 
in.  in  length.     Tails  of  the  ripened  akenes  1  in.  long,  silky.     Rich 
woods  and  river  banks  S.* 

2.  C.  viorna,  L.      LEATHER    FLOWER.      Stem  climbing,  nearly 
smooth,   6-10  ft.  long.     Leaves  usually  pinnately   compound,  the 
lowest  pair  often  compound  in  threes  and  the  upper  pair  simple. 
Leaflets  usually  5-7,  oblong-ovate  or  oval,    acute,  firm,  entire,  or 
lobed.    Calyx  bell-shaped,  nodding  ;  sepals  ovate,  taper-pointed  with 
a  short,  recurved  point,  thick  and  leathery,  reddish-purple,  1  in.  long. 
Tails  of  the  akenes  plumose,  l£  in.  long,  brownish.    On  river  banks 
and  rich  soil.* 

XIII.    RANUNCULUS,  Tourn. 

Annual  or  perennial  herbs.  Leaves  alternate,  usually 
deeply  lobed  or  parted.  Flowers  axillary  or  in  corymbs, 
white  or  yellow.  Sepals  3-5.  Petals  3-5,  flat,  with  a  small 


DICOTYLEDONOUS  PLANTS  83 

pit  or  scale  inside  at  the  narrowed  base.  Stamens  usually 
numerous.  Pistils  few  or  several  in  a  head.  Akenes  flattened, 
pointed.* 

1.  R.  pusillus,  Poir.     Low  SPEARWORT.     Perennial.    Stems  sev- 
eral, erect  or  ascending,  branched,  smooth,  6-15  in.  high.     Leaves 
entire  or  slightly  toothed,  the  lower  round  or  cordate,  long-petioled, 
the  upper  lanceolate  or  elliptical,  nearly  or  quite  sessile.     Flowers 
very  small,  about  £  in.  wide,  yellow.     Petals  1-5,  as  long  as  the 
sepals.     Stamens  3-10.     Akenes  smooth,  with  a  very  short  point. 
On  muddy  banks.* 

2.  R.  abortivus,  L.     SMALL-FLOWERED   CROWFOOT.      Perennial. 
Stems  smooth,  branching,  12-18  in.  high.     Root-leaves  round-cor- 
date, crenate,  petioled.     Stem-leaves  3-5-parted,  with  wedge-shaped 
or  linear  divisions,  sessile.     Flowers  very  small,  pale  yellow.     Sepals 
reflexed,  longer  than  the  petals.     Akenes  in  a  globose  head,  smooth, 
without  a  beak.     Common  on  wet  ground  and  waste  places.* 

3.  R.  recurvatus,  Poir.     HOOKED  CROWFOOT.     Perennial.     Stem 
erect,  hairy,  1-2  ft.  high.    Leaves  all  nearly  alike,  petioled,  3-5-lobed 
with  the  lobes  wedge-shaped,  cut  or  toothed  at  the  apex.     Flowers 
small,  pale  yellow.     Petals  minute,  shorter  than  the  reflexed  sepals. 
Akenes  in  a  globular  head,  smooth,  with  a  slender,  recurved  beak. 
On  low  ground.* 

4.  R.  pennsylvanicus,  L.    BRISTLY  CROWFOOT.    Perennial.    Stems 
rough-hairy,  erect,  2-3  ft.  high.     Leaves  compound  in  threes,  on 
long   and   very  hairy  petioles;    leaflets   long-stalked,  3-parted,    the 
divisions  sharply  lobed  or  toothed.     Flowers  small.     Petals  yellow, 
shorter  than  the  sepals.     Akenes  flat,  smooth,  in  oblong  heads,  beak 
broad  and  straight.     On  low  ground.* 

5.  R.  bulbosus,  L.     BULBOUS  BUTTERCUP,  EARLY   BUTTERCUP. 
Stem  upright,  from  a  solid  bulb  about  as  large  as  a  filbert,  about 
1  ft.  high,  hairy.     Root-leaves  3-divided,  the  divisions  lobed  and 
cleft.     Peduncles  furrowed.     Flowers  large  and  showy  (^  to  1  in.  in 
diameter).    Sepals  strongly  reflexed.    Petals  roundish,  wedge-shaped 
at  the  base.     Akenes  with  a  very  short  beak.      Introduced  from 
Europe.     Common  in  grass  fields  in  New  England. 

6.  R.  acris,  L.     TALL   BUTTERCUP.     Erect,  hairy,  2-3  ft.  high. 
Leaves  3-7-parted,  the    divisions  of  the  lower  ones  wedge-shaped, 
deeply  cut  and  lobed.     Peduncles  not  furrowed.     Sepals  spreading, 
downy.     Petals  obovate,  a  little  smaller  and  paler  yellow  than  in 
No.  5.     A  common  weed,  introduced  from  Europe,  in  grass  fields 
and  elsewhere,  especially  eastward. 


84  FOUNDATIONS  OF  BOTANY 


XIV.     THALICTRUM,  L. 

Erect  perennial  herbs.  Leaves  compound,  with  stipules. 
Flowers  in  panicles  or  racemes,  often  somewhat  monoecious 
or  dioecious,  wind-fertilized.  Sepals  4-5,  petal-like.  Petals 
none.  Stamens  many.  Carpels  few  or  many  ;  ovule  1.  Fruit 
a  small  head  of  akenes.  [The  following  species  are  both 
usually  dioecious.] 

1.  T,  dioicum,  L.      EARLY  MEADOW  RUE.     Plant  1-2  ft.  high, 
smooth  and  pale  or  with  a  bloom.    Leaves  all  petioled,  most  of  them 
thrice  compound  in  threes  ;  leaflets  thin  and  delicate,  roundish,  3-7- 
lobed.     Flowers  in  slender  panicles,  purplish  or  greenish  ;  staminate 
ones  with  slender,  thread-like  filaments,  from  which  hang  the  con- 
spicuous yellowish  anthers.     Rocky  woods  and  hillsides. 

2.  T.    polygamum,    Muhl.     TALL   MEADOW   RUE.     Stems   from 
fibrous  roots,  tall  and  coarse,  nearly  or  quite  smooth,  4-8  ft.  tall. 
Leaves  twice  compound,  those  of  the  stem  sessile,  the  others  long- 
petioled  ;  leaflets  oval  or  oblong,  often  cordate,  smooth  or  downy 
beneath,  quite  variable  in  size  on  the  same  plant.    Flowers  small, 
in  large  panicles.     Sepals  4    or  5,  white.     Filaments   club-shaped. 
Akenes  short-stalked.     Thickets  and  meadows  E. 


33.    BERBERIDACE^.     BARBERRY  FAMILY. 

Herbs  or  shrubs.  'Leaves  alternate,  simple  or  compound, 
usually  without  stipules.  Sepals  petal-like.  Petals  hypogy- 
nous,  distinct,  their  number  some  multiple  of  2,  3,  or  4,  never 
of  5.  Stamens  one  opposite  each  petal,  anthers  opening  by 
2  uplifted  lids.  Pistil  1,  1-celled,  ovules  2  or  more.  Fruit 
a  berry  or  capsule. 

I.    BERBERIS,  L. 

Spiny  shrubs  with  yellow  wood.  Leaves  spinous-toothed, 
jointed  on  the  very  short  petiole,  often  reduced  to  3-7-cleft 
spines.  Flowers  in  racemes,  solitary,  or  in  pairs.  Sepals 
8—9,  the  outer  minute.  Petals  6,  each  with  2  nectar  glands 
at  the  base.  Stamens  6.  Ovules  few.  Berry  1-2-seeded ; 
seeds  bony-coated. 

1.  B.  vulgaris,  L.  COMMON  BARBERRY.  A  shrub  4-6  ft.  high. 
Leaves  obovate,  spinous-serrate  ;  those  on  the  old  shoots  mere 


DICOTYLEDONOUS  PLANTS  85 

spines.  Flowers  pale  yellow,  in  drooping  racemes.  Stamens  irrita- 
ble, closing  quickly  toward  the  center  of  the  flower  when  touched. 
Berry  £  in.  long,  nearly  ellipsoidal  in  shape,  scarlet  or  orange-scarlet, 
very  acid,  eatable  when  cooked.  Cultivated  from  Europe  and  intro- 
duced in  eastern  New  England  and  locally  in  the  upper  Mississippi 
valley. 

2.  B.  Thunbergii,  DC.  A  low  shrub.  Leaves  entire,  turning 
red  and  remaining  so  for  a  considerable  time  in  autumn.  Flowers 
solitary  or  in  pairs.  Berries  bright  red,  remaining  on  the  branches 
all  winter.  Cultivated  from  Japan. 

II.    CAULOPHYLLUM,  Michx. 

A  perennial  smooth  herb,  1-2-J-  ft.  high.  Leaf  large,  single, 
sessile,  thrice  compound  in  threes,  borne  high  up  on  the  stem  ; 
there  is  also  a  large,  very  compound  radical  leaf.  Flowers 
racemed  or  panicled,  yellowish-green.  Sepals  6,  with  3  bract- 
lets.  Petals  6,  gland-like,  somewhat  curved  inward  at  the 
tip,  much  smaller  than  the  sepals.  Pistil  2-ovuled,  the  ovary 
soon  bursting  open  and  leaving  the  2  blue  seeds  to  ripen  naked. 

1.  C.   thalictroides,   Michx.      BLUE    COHOSH,   PAPPOOSE    ROOT. 

Whole  plant  purplish  and  covered  with  a  bloom  when  young. 
Flowers  appearing  before  the  leaf  is  fully  developed.  Rich  woods. 

HI.     PODOPHYLLUM,  L. 

Perennial.  Stem  simple,  smooth,  erect,  12-15  in.  tall,  bear- 
ing 2  leaves  with  a  large  white  flower  between  them.  Sepals 
6,  falling  off  as  the  flower  opens.  Petals  6-9,  obovate.  Sta- 
mens twice  as  many  as  the  petals.  Pistil  1,  stigma  large,  flat, 
sessile.  Fruit  berry-like,  1-celled,  many-seeded.* 

1.  P.  peltatum,  L.  MAY-APPLE.  Rootstock  rather  large.  Leaves 
orbicular,  shield-shaped,  5-9-lobed  and  toothed,  smooth,  9-12  in. 
wide.  Flowers  1—2  in.  wide,  on  a  peduncle  1—2  in.  long.  Stamens 
prominent,  anthers  opening  longitudinally.  Fruit  1^-2  in.  long, 
oval,  fragrant,  edible  ;  each  seed  surrounded  by  a  pulpy  covering. 
In  rich  woods.  The  roots  and  leaves  are  used  in  medicine.* 


34.   MAGNOLIACEJE.     MAGNOLIA  FAMILY. 

Trees  or  shrubs.     Leaves  alternate,  not  toothed  or  serrate. 
Flowers  solitary,  large,  and  showy.     Floral  envelopes  and 


86  FOUNDATIONS   OF   BOTANY 

stamens  hypogynous.  Calyx  and  corolla  colored  alike,  the 
parts  of  the  perianth  forming  3  or  more  circles  of  3  parts 
each.  Stamens  many.  Carpels  many,  usually  cohering  over 
the  long  receptacle  and  forming  a  sort  of  cone-shaped  fruit, 
which  may  be  either  fleshy  or  dry. 

I.    MAGNOLIA. 

Aromatic  trees  or  shrubs  ;  leaves  alternate,  often  in  clus- 
ters at  the  ends  of  the  branches,  entire,  usually  thick  and 
leathery ;  stipules  large,  quickly  deciduous  ;  flowers  termi- 
nal, showy,  perfect ;  sepals  3,  caducous  ;  petals  6-12,  in  2-4 
rows,  concave;  stamens  numerous  ;  ovaries  numerous,  1-celled, 
2-seeded,  the  mature  follicles  opening  at  the  beak,  and  the 
fleshy  seeds  remaining  for  some  time  suspended  by  slender 
threads.* 

1.  M.    grandiflora,   L.     LARGE-FLOWERED   MAGNOLIA.     A   large 
tree    with    spreading  branches    and    a   rounded   top  ;    bark    nearly 
smooth.     Leaves  very  thick,  evergreen,  smooth  and  shining  above, 
rusty-downy  beneath,  entire,  oval  or  oblong,  6-9  in.  long.     Flowers 
white,  very  fragrant,  6-9  in.  in  diameter.     Petals  9  or  more,  obovate, 
concave.     Fruit  a  rusty-downy  cone  3-4  in.  long,  seeds  bright  scarlet. 
Common  on  light  soils  in  Arkansas  and  the  Gulf  States.* 

2.  M.  Fraseri,  Walt.     LONG-LEAVED  UMBRELLA  TREE.     A  small 
tree  with  a  slender  trunk  and  widely  spreading  branches.     Leaves 
clustered  at  the  ends  of  the  branches,  deciduous,  oblong  or  obovate, 
contracted,  cordate  and  eared  at  the  base,  smooth  on  both  sides, 
8-12  in.  long  ;  petioles  slender.     Flowers  white  and  fragrant,  6  in. 
broad.     Petals  longer  than  the  sepals,  spatulate  or  oblong,  obtuse  at 
the  apex,  narrowed  at  the  base.    Cone  3-4  in.  long,  pink  at  maturity. 
In  rich  woods  S.* 

3.  M.   macrophylla,  Michx.      LARGE-LEAVED    UMBRELLA  TREE. 
A  small  tree  with  gray  bark.     Leaves  clustered  at  the  ends  of  the 
branches,  oblong  or  obovate,  obtuse  at  the  apex,  cordate  at  the  base, 
green  and  glabrous  above,  white  and  downy  beneath,  H-3  ft.  long- 
petioles  stout.     Flowers  white  with  a  purple  center,  fragrant,  8-12 
in.  wide ;  petals  oblong,  obtuse,  two  or  three  times  as  long  as  the 
sepals.     Cone  ovate,  4-6  in.  long,  bright  red  at  maturity.     Shady 
woods  on  light  soil  S.* 

4.  M.  virginiana,  L.     SWEET  BAY.     A  small  tree  with  light  gray 
bark.       Leaves    scattered  on   the    branches,    evergreen,    thick    and 
leathery,  oval  or  oblong,  smooth,  and  green  above,  white  and  with 


DICOTYLEDONOUS   PLANTS  87 

a  bloom,  downy  beneath,  4-6  in.  long.  Flowers  white,  fragrant,  2-3 
in.  in  diameter;  petals  9,  concave.  Cone  1^-2  in.  long,  pink.  Com- 
mon in  swamps  and  along  streams,  New  York  and  southward  (a 
few  in  eastern  Massachusetts).  The  leaves  often  used  in  flavoring 
soups,  etc. 

II.     LIRIODENDRON,  L. 

A  large  tree  with  rough,  dark-colored  bark.  Leaves  scat- 
tered on  the  branches,  deciduous,  3-lobed,  truncate,  stipuled, 
petioled.  Flowers  perfect.  Sepals  3,  reflexed.  Petals  6, 
erect.  Stamens  numerous.  Ovaries  numerous,  2-ovuled, 
cohering  over  each  other  on  the  elongated  receptacle,  never 
opening,  deciduous.1* 

1.  L.  tulipifera,  L.  TULIP  TREE.  The  largest  tree  in  the  family. 
Leaves  roundish  in  outline,  mostly  3-lobed,  the  terminal  lobe  trun- 
cate or  broadly  notched,  usually  heart-shaped  at  the  base,  smooth, 
green  above,  lighter  beneath.  Petioles  slender.  Flowers  terminal, 
bell-shaped,  greenish-yellow  marked  with  orange.  Petals  obovate, 
obtuse,  about  as  long  as  the  sepals.  Mature  cones  ovate,  acute, 
2-3  in.  long.  Common  on  low  ground,  Pennsylvania  and  S.  Often 
called  "  white  wood  "  or,  incorrectly,  "  white  poplar."  Wood  valua- 
ble for  making  boxes  and  light  furniture.* 


35.   CALYCANTHACE^E.     CALYCANTHUS  FAMILY. 

Shrubs.  Leaves  opposite,  entire,  without  stipules.  Flowers 
solitary,  often  sweet-scented.  Sepals  and  petals  numerous, 
the  outer  sepals  bract-like.  Stamens  many,  short,  the  inner 
ones  usually  sterile.  Ovaries  several,  inserted  on  the  inside 
of  an  irregular,  hollow,  pear-shaped  receptacle  something  like 
a  large  rose-hip,  forming  1-seeded  akenes  in  fruit. 

CALYCANTHUS,  L. 

Shrubs,  4-8  ft.  tall;  branches  opposite.  Leaves  oval, 
downy  beneath,  short-petioled  5  both  leaves  and  bark  aro- 
matic. Sepals  and  petals  many,  in  several  rows,  somewhat 
fleshy,  indistinguishable.  Pistils  several,  inserted  on  the 
inner  side  of  the  persistent  calyx-tube.  Mature  fruit  pear- 
shaped,  dry,  enclosing  the  akenes.* 


88  FOUNDATIONS   OF  BOTANY 

1.  C.  floridus,  L.  SWEET-SCENTED  SHRUB,  STRAWBERRY  BUSH, 
SPICE  BUSH,  SHRUB.  A  widespreading  bush,  4—8  ft.  high  ;  twigs 
downy.  Leaves  oval  or  oblong,  acute  or  taper-pointed,  rough 
above,  downy  beneath,  2-3  in.  long.  Flowers  1  in.  wide,  brownish- 
purple,  very  fragrant ;  sepals  united  below  to  form  a  cup,  on  the 
inside  of  which  the  other  parts  of  the  flower  are  inserted,  cup  leafy- 
bracted  on  the  outside.  Banks  of  streams  and  rich  hillsides  S., 
often  cultivated.* 

36.   ANONACEJE.     PAWPAW  FAMILY. 

Trees  or  shrubs.  Leaves  alternate,  entire ;  pinuately  veined. 
Flowers  perfect,  hypogynous,  axillary,  solitary.  Calyx  of  3 
sepals,  corolla  of  6  thickish  petals  in  2  rows.  Stamens  many, 
filaments  very  short.  Pistils  several  or  many,  becoming 
fleshy  or  pulpy  in  fruit. 

ASIMINA,  Adans. 

Shrubs  or  small  trees.  Leaves  deciduous.  Flowers  nod- 
ding. Sepals  3,  ovate.  Petals  6,  the  3  outer  ones  larger 
and  spreading.  Stamens  very  numerous,  crowded  on  the 
globular  receptacle.  Ovaries  3-15,  sessile,  1-celled,  several- 
ovuled.  Fruit  a  large,  fleshy,  oblong  berry,  seeds  large, 
horizontal.* 

1.  A.  triloba,  Dunal.  PAWPAW.  A  small  tree,  10-20  ft.  high  ; 
bark  nearly  smooth,  lead-colored.  Leaves  oblong-obovate,  acute  at 
the  apex,  obtuse  at  the  base,  rusty-downy  when  young  and  becoming 
smoother  with  age,  6-10  in.  long.  Flowers  on  branches  of  the 
previous  season,  appearing  before  or  with  the  leaves  ;  the  short 
peduncles  and  the  sepals  brown-downy.  Petals  purple,  obovate,  3-4 
times  longer  than  the  sepals.  Fruit  3—5  in.  long,  edible  when  ripe. 
Common  on  banks  of  streams,  especially  S.  and  S.  W.  The  bark 
is  very  tough  and  is  often  used  in  the  place  of  rope.* 


37.   LAURACEJE.     LAUREL  FAMILY. 

Aromatic  plants,  nearly  always  trees  or  shrubs.  Leaves 
alternate,  simple,  usually  entire,  and  marked  with  translucent 
dots.  Calyx  regular,  hypogynous,  of  4  or  6  colored  sepals. 


DICOTYLEDONOUS  PLANTS  89 

Stamens  in  3  or  4  circles  of  3  each,  the  anthers  opening  by 
valves.     Style  single.     Fruit  a  1-seeded  berry  or  stone-fruit. 

I.    SASSAFRAS,  Nees. 

A  tree  with  rough,  yellowish  bark  and  a  spreading  top. 
Leaves  deciduous,  entire  or  2-3-lobed.  Flowers  dioecious,  in- 
volucrate,  at  the  end  of  the  twigs  of  the  previous  season. 
Calyx  6-parted,  persistent  in  the  pistillate  flowers.  Stamens 
9,  in  3  rows.  Pistillate  flowers  with  4-6  abortive  stamens 
and  a  single  ovary.  Fruit  a  stone-fruit.* 

1.  S.  officinale,  Nees.  SASSAFRAS.  A  tree,  usually  small  and 
slender,  but  sometimes  with  a  trunk  3  ft.  in  diameter  and  125  ft. 
high.  Leaves  oval,  entire,  mitten-shaped  or  3-lobed,  downy  when 
young  but  becoming  smooth  with  age,  dark  green  above,  paler 
below,  petiolate.  Racemes  several  in  a  cluster,  peduncled  ;  flowers 
yellow.  Stamens  about  as  long  as  the  sepals.  Fruit  dark  blue, 
ovoid,  on  thickened,  red  pedicels.  All  parts  of  the  tree  aromatic  ; 
trees  producing  pistillate  flowers  rare.  Common.  The  wood  is 
valuable  for  cabinet-making,  and  an  aromatic  oil  is  extracted  from 
the  bark.* 

H.    LINDERA,  Thunb. 

Shrubs  ;  leaves  deciduous,  entire.  Flowers  in  lateral, 
sessile  clusters,  appearing  before  the  leaves,  dioecious  or 
somewhat  monoecious.  Involucre  of  4  scales.  Stamens  9  in 
the  staminate  flowers,  filaments  slender.  Pistillate  flowers 
with  12-15  abortive  stamens  and  a  single  globose  ovary  with 
a  short  style.* 

1.  L.  Benzoin,  Blume.  SPICE  BUSH.  A  shrub,  5-15  ft.  high, 
with  smooth  bark  and  slender  twigs.  Leaves  oblong-obovate,  acute 
at  the  base,  pale  and  downy  beneath,  becoming  smooth  when  old  ; 
petioles  short.  Flowers  about  as  long  as  the  pedicels,  yellow,  very 
fragrant.  Ovary  about  as  long  as  the  style.  Fruit  an  obovoid,  red 
stone-fruit  about  ^  in.  long,  on  a  slender  pedicel.  Banks  of  streams 
and  damp  woods.  Twigs  and  leaves  quite  aromatic.* 


38.   PAPAVERACEJE.     POPPY  FAMILY. 

Annual  or  perennial  herbs,  often  with  milky  juice.    Leaves 
sometimes  all  radical,  stem-leaves  usually  alternate  without 


90  FOUNDATIONS   OF   BOTANY 

stipules.  Flowers  perfect,  regular  or  irregular.  Sepals 
usually  2,  shed  as  the  flower  opens.  Petals  4-12,  falling 
early.  Stamens  numerous  or  6  (in  2  sets),  4,  or  2.  Carpels 
2-16.  Fruit  a  capsule. 

I.    ESCHSHOLTZIA,  Cham. 

Annual  or  perennial  herbs.  Leaves  pale  or  bluish-green, 
usually  cut  into  very  narrow  divisions.  Sepals  united  into  a 
pointed  cap,  which  falls  off  in  one  piece  as  the  flower  opens. 
Petals  4,  orange  or  yellow.  Stamens  many,  with  long  anthers. 
Stigmas  2-6,  spreading.  Pods  long  and  slender,  grooved.  Re- 
ceptacle often  surrounded  by  a  rim  on  which  the  calyx  rests. 

1.  E.  californica,  Cham.  Annual  or  perennial,  with  rather  suc- 
culent leafy  stems.  Flowers  large  and  showy,  yellow  or  orange- 
yellow.  Receptacle  top-shaped,  with  a  broad  rim.  Cultivated  from 
California. 

H.     SANGUINARIA,  Dill. 

Perennial.  Rootstock  thick,  horizontal,  joints  and  scars 
of  previous  growths  persistent  several  years  ;  juice  orange- 
colored.  Leaves  on  long  petioles,  kidney-shaped.  Scape 
1-flowered.  Sepals  2,  falling  off  as  the  flower  opens.  Petals 
8-12.  Ovary  1,  stigmas  2 ;  capsule  oblong,  seeds  crested.* 

1.  S.  canadensis,  L.  BLOODROOT.  Leaves  and  scape  with  a 
bloom ;  leaves  palmately  5-9-lobed,  lobes  rounded  or  toothed ;  scapes 
naked,  nearly  as  long  as  the  petioles.  Flowers  white,  1  in.  or  more 
wide.  Petals  oblong  or  obovate,  quickly  deciduous.  Capsule 
1 -celled,  2-valved,  the  valves  separating  from  the  persistent  placentae 
at  maturity.  In  rich,  open  woods.* 

m.     CHELIDONIUM,  L. 

Erect,  branched,  perennial  herbs  with  yellow  juice.  Leaves 
much  divided.  Flowers  yellow.  Sepals  2,  falling  as  the 
flower  opens.  Petals  4.  Ovary  1-celled  ;  style  dilated  at  the 
top,  with  2  adnate  stigmas.  Capsule  linear. 

1.  C.  majus,  L.  CELANDINE.  Stem  1-2  ft.  high,  brittle,  slightly 
hairy,  leafy.  Leaves  once  or  twice  pinnate.  Flowers  small.  A  rather 
common  weed  in  yards  and  along  fences.  Introduced  from  Europe. 


DICOTYLEDONOUS   PLANTS  91 


IV.    PAPAVER. 

Annual  or  perennial  herbs  with  milky  juice.  Stem  erect, 
smooth,  or  rough-hairy,  branching  above.  Leaves  more  or 
less  lobed  or  dissected.  Flower-buds  nodding,  flowers  showy. 
Sepals  commonly  2,  falling  off  as  the  flower  opens.  Petals 
4-6.  Stamens  many.  Stigma  disk-like,  ovules  many,  borne 
on  many  inwardly  projecting  placentae.* 

1.  P.    somniferum,    L.      OPIUM  POPPY.      Annual;    stem   erect, 
branched  above,  smooth  and  with  a  bloom,  2-3  ft.  high.     Leaves 
oblong,  irregularly  lobed  or  cut,  sessile,  clasping.     Flowers  nearly 
white,  with  a  purple  center,  large  and  showy,  on  long  peduncles. 
Capsule  globose,  seeds   minutely   pitted.     About   old  gardens  and 
waste  places.     Cultivated  in  southern  Asia,  where  the  juice  of  the 
capsules  is  dried  to  make  opium.* 

2.  P.  dubium,  L.     CORN  POPPY.     Annual ;  stem  slender,  branch- 
ing, 1-2  ft.  tall.     Leaves  pinnatifid,  the  lower  petioled,  the  upper 
sessile.     Flowers   large    and   showy,    usually    red;    capsule    long- 
obovoid,  smooth.     In  cultivated  ground.     Both  the  species  named 
are  often  cultivated  in  gardens  and  produce  double  flowers.* 

3.  P.    orientate,   L.     ORIENTAL    POPPY.     A   large,   rough-hairy 
perennial.     Leaves  large,  deep  green,  almost  pinnate.     Flower  very 
large,  deep  red.     Cultivated  from  the  eastern  Mediterranean  region. 

4.  P.    nudicaule,    L.     ICELAND    POPPY.     A   delicate   but   rough- 
hairy  perennial   plant.      Leaves   all   radical,   pale,    pinnately   cut. 
Flowers  yellow-orange   or  white,  borne   singly  on   rather  slender, 
hairy  scapes.     Cultivated  from  Europe. 


V.    DICENTRA,  Borkh. 

Smooth,  delicate  herbs  with  watery  juice.  Leaves  com- 
pound in  threes  and  finely  cut.  Flowers  racemed,  nodding. 
Sepals  2,  small  and  scale-like.  Petals  4,  slightly  united  to 
form  a  heart-shaped  or  2-spurred  corolla  (Fig.  12),  the  inner 
pair  spoon-shaped,  enclosing  the  stamens  and  pistil.  Stamens 
6  ;  the  filaments  somewhat  united  into  2  sets,  and  the  anthers 
in  2  sets  close  to  the  stigma.  Stigma  2-crested.  Pod  10-20- 
seeded. 

1.  D.  Cucullaria,  DC.  DUTCHMAN'S  BREECHES,  BREECHES 
FLOWER.  A  low,  stemless  perennial,  with  a  delicate  scape  and  a 
cluster  of  root-leaves  with  linear  divisions  from  a  sort  of  bulb  made 


92 


FOUNDATIONS   OF   BOTANY 


of  small,  scaly  grains.  Flowers  in  a  4-10-flowered  simple  raceme,  not 
fragrant.  Spurs  of  the  corolla  longer  than  the  pedicels;  corolla 
mostly  white  with  a  yellowish  tip.  Rich  woods,  common. 

2.  D.  canadensis,  DC.      SQUIRREL  CORN,  WILD  HYACINTH.     A 
low,  stemless  perennial,  with  scape  and  leaves  much  as  in  No.  1,  and 
with  small  yellow  tubers  looking  like  grains  of  corn  scattered  along 
the   underground   shoots.     Corolla   only  heart-shaped  at  the  base, 
whitish  or  flesh-colored,  very  fragrant.     Rich  woods. 

3.  D.  spectabilis,  DC.     BLEEDING  HEART,  EAR  DROPS.     Stems 
branching,  recurved.     Leaves  large,  twice  compound  in  threes,  the 
divisions  rather  broad,  like  those  of  the  common  peony.     Racemes 
long,  drooping,  many-flowered.     Flowers  large,  heart-shaped,  bright 
pink.     Cultivated  from  China. 


VI.    ADLUMIA,  Raf. 

A  delicate  climbing  biennial.  Leaves  thrice-pinnate,  cut- 
lobed.  Sepals  2,  very  small.  Petals  4,  all  united  into  a  corolla 
which  is  slightly  heart-shaped  or  2-knobbed  at  the  base,  remain- 
ing as  a  spongy  covering  over  the  small,  few-seeded  pod. 


A  B 

FIG.  12.  —  Flower  of  Dicentra. 

A,  view  of  flower  partly  dissected  ;  p,  the  larger  outer  petals  ;  p',  the  spoon- 
shaped  inner  petals  ;  £,  floral  diagram. 


1.  A.    cirrhosa,   Raf.      MOUNTAIN   FRINGE,    ALLEGHANY   VINE. 

Climbing  several  feet   high  by   the   leaf-stalks.     Flowers   pinkish- 
white.     Rocky  hillsides,  often  cultivated. 


DICOTYLEDONOUS  PLANTS  93 


VII.     CORYDALIS,  Vent. 

Leafy-stemmed  Biennial  herbs  (the  American  species). 
Leaves  much  divided,  alternate  or  nearly  opposite.  Racemes 
terminal  or  opposite  the  leaves.  Sepals  2,  small.  Petals  4 ; 
corolla  with  a  single  spur  at  the  base,  on  the  upper  side. 
Capsule  many-seeded. 

1.  C.    glauca,   Pursh.     PALE    CORYDALIS.     Plant  erect,  covered 
with  a  bloom.     Flowers  pink-purple  with  yellow  tips.     Spur  of  the 
corolla  very  short  and  rounded.     Rocky  woods. 

2.  C.  aurea,  Willd.    GOLDEN  CORYDALIS.    A  low,  spreading  plant, 
finally  ascending.      Corolla  bright  yellow,  1-2  in.  long;  the  spur 
shorter  than  the  pedicel,  somewhat  bent.     Shaded,  rocky  banks. 

39.   CRUCIFERJE.     MUSTARD  FAMILY. 

Herbs  with  pungent,  watery  juice  and  alternate  leaves  with- 
out stipules.  Sepals  4,  often  falling  off  early.  Petals  usually 
4,  arranged  in  the  form  of  a  cross.  Stamens  6,  the  2  outer 
ones  shorter  than  the  4  inner  ones.  Fruit  generally  a  pod, 
divided  into  two  cells  by  a  thin  partition  which  stretches 
across  from  one  to  the  other  of  the  two  placentae.  The 
flowers  throughout  the  family  are  so  much  alike  that  the  gen- 
era and  species  cannot  usually  be  determined  without  examin- 
ing the  tolerably  mature  fruit. 

A. 

Pods  short  and  flattened,  contrary  to  the  partition,  splitting  open  when  ripe. 
Pod  roundish.  Lepidium,  I. 

Pod  triangular,  inversely  heart-shaped.  Capsella,  IX. 

B. 

Pods  globular  or  cylindrical,  splitting  open  when  ripe. 

(a)  Pods  globular.     Flowers  white.     Petals  much  longer 

than  the  calyx.  Cochlearia,  II. 

(5)  Pods  cylindrical;  seeds  ellipsoid.     Flowers  very  small, 

yellow.  Sisymbrium,  III. 


94  FOUNDATIONS   OF   BOTANY 

(c)  Pods  cylindrical ;  seeds  globular.  Flowers  of  moderate 
size,  yellow.  Brassica,  IV. 

(e?)  Pods  cylindrical.  Flowers  white.  Or  pods  ovoid  or 
ellipsoid.  Flower  yellowish.  Aquatic  plants,  or 
growing  in  wet  soil.  Nasturtium,  VI. 

C. 

Pods   elongated,  often  jointed,  tapering  toward  the  tip,  never  splitting 
open.  Raphanus,  V. 

D. 

Pods  flattened  parallel  to  the  partition,  splitting  open  when  ripe. 

(a)  Wild  species  leafy-stemmed ;  growing  in  or  near  water. 

Pods  linear.  Cardamiiie,  VII. 

(&)  Wild  species ;  stems  naked  below,  bearing  only  2  or  3 

leaves.     Pods  lanceolate.  Dentaria,  VIII. 

(c)  Wild  species  ;  leafy-stemmed ;  growing  on  dry  ground 

or  rocks.     Pods   linear;    seeds   usually   winged   or 
margined.  Arabia,  X. 

(d)  Cultivated  species.     Pods  round  or  roundish. 

Lobularia,  XI. 

(e)  Cultivated  species,  covered  with   a   grayish   down   of 

star-shaped  hairs.     Pods  cylindrical. 

Matthiola,  XII. 

I.    LEPIDIUM,  Tourn. 

Annual ;  stem  erect,  or  sometimes  diffuse.  Leaves  entire, 
toothed,  or  pinnately  divided.  Flowers  in  a  terminal  raceme, 
small,  white.  Petals  short,  sometimes  wanting.  Stamens  2, 
4,  or  6.  Pod  rounded  or  obcordate,  flattened  contrary  to  the 
partition.* 

1.  L.  virginicum,  L.  PEPPERGRASS,  BIRDS'  PEPPER,  TONGUE- 
GRASS.  Stem  erect,  smooth,  much  branched,  1-2  ft.  high.  Lower 
leaves  obovate  in  outline,  pinnately  cut  with  dentate  lobes ;  upper 
leaves  lanceolate,  dentate,  slightly  downy.  Flowers  on  slender 
pedicels,  petals  present,  sometimes  reduced  in  the  later  flowers. 
Stamens  2.  Pod  round.  A  weed  growing  in  waste  places.* 


DICOTYLEDONOUS    PLANTS  95 


II.     COCHLEARIA,  Tourn. 

Perennial  herbs.  Leaves  entire  or  pinnate.  Flowers 
small,  white.  Sepals  short.  Petals  with  short  claws.  Pods 
globular  or  ellipsoid. 

1.  C.  Armoracia,  L.  HORSE-RADISH.  A  coarse  herb  with  large 
leaves  from  stout,  long,  cylindrical  rootstocks  filled  with  a  very 
sharp,  biting  juice.  Root-leaves  long-petioled,  linear-oblong,  obtuse, 
regularly  scalloped ;  stem-leaves  sessile.  Racemes  in  panicles. 
Pods  obovoid,  on  long,  slender  pedicels.  Seeds  seldom  or  never 
ripening.  Probably  from  Europe  ;  cultivated  and  often  introduced 
in  damp  ground. 

HI.    SISYMBRIUM,  Tourn. 

Annual  or  biennial  herbs.  Radical  leaves  spreading  ;  stem- 
leaves  alternate,  often  eared  at  the  base.  Flowers  in  loose 
racemes,  usually  yellow,  often  bracted.  Pods  generally  nar- 
rowly linear,  cylindrical  or  4-6-angled.  Seeds  many,  ellip- 
soid, not  margined. 

1.  S.   canescens,  Nutt.     TANSY  MUSTARD.     Stem   1-2  ft.  high. 
Leaves  twice   pinnately   cut,  usually   covered   with    grayish   down. 
Flowers  very  small,  yellowish.     Pods  oblong,  club-shaped,  4-angled, 
borne  on  pedicels  projecting  almost  horizontally  from  the  stem,  in 
long  racemes.     Common  westward. 

2.  S.  officinale,  Scop.    HEDGE  MUSTARD.    Stems  branching,  stiff. 
Leaves  runcinate-toothed  or  lobed.     Flowers  very  small,  pale  yel- 
low.    Pods  somewhat  6-sided,   awl-shaped,   closely  pressed  against 
the  stem.     An  unsightly  weed  in  waste  ground,  introduced  from 
Europe. 

IV.    BRASSICA,  Tourn. 

Branching  herbs.  Leaves  often  pinnately  cut.  Flowers 
in  racemes,  rather  large,  yellow.  Sepals  spreading.  Pods 
nearly  cylindrical,  sometimes  tipped  with  a  beak  which  does 
not  open.  Seeds  globular. 

1.  B.  arvensis,  Boiss.  CHARLOCK.  Stem  1-2  ft.  high;  it  and  the 
leaves  rough-hairy.  Upper  leaves  rhombic-toothed  or  no.  Flowers 
£-f  in.  across,  somewhat  corymbed,  bright  yellow.  Pods  knotty, 
spreading,  at  least  %  of  each  consisting  of  a  2-edged,  1-seeded  beak. 
A  showy,  troublesome  weed  in  grain  fields,  introduced  from  Europe. 


96  FOUNDATIONS   OF   BOTANY 

2.  B.  juncea,  Coss.     Similar  to  the  preceding,  but  nearly  or  quite 
smooth.     Pedicels    slender.     Beak  of    the   cylindric   pod    slender, 
conical,  not  containing  a  seed.     Recently  introduced  from  Asia  and 
becoming  very  abundant  eastward. 

3.  B.  alba,  Boiss.     WHITE  MUSTARD.     Stem  2-5  ft.  high,  with 
reflexed  hairs.     Upper  leaves  pinnately  cut.     Pods  borne  on  spread- 
ing pedicels,  bristly,  with  a  sword-shaped,  1-seeded  beak  occupying 
more  than  half  their  length.     Seeds  pale.     Cultivated  from  Europe 
and  introduced  to  some  extent. 

4.  B.  nigra,  Koch.     BLACK  MUSTARD.     Stem  3-6  ft.  high,  some- 
what hairy.     Lower  leaves  lyrate  with  the  terminal  lobe  much  the 
longest,    stem-leaves   linear-lanceolate,    entire  or   toothed,    smooth. 
Pods  awl-shaped,  4-angled,  smooth,  lying  against  the  stem.     Seeds 
brownish,  more  biting  than  in  No.  2.     Cultivated  from  Europe  and 
introduced. 

V.     RAPHANUS,  Tourn. 

Annual  or  biennial  herbs.  Boot-leaves  lyrate.  Flowers  in 
long  racemes,  white  or  yellow,  purple-veined.  Sepals  erect. 
Pods  rather  long,  slender-beaked,  not  splitting  open  but  some- 
times breaking  across  into  1-seeded  joints. 

1.  R.  Raphanistrum,  L.  WILD  RADISH,  JOINTED  CHARLOCK. 
A  stout,  hairy  annual  1—2  ft.  high.  Leaves  cut  into  remote  seg- 
ments, which  are  coarsely  toothed  or  serrate  ;  terminal  segment 
largest.  Flowers  yellow,  turning  whitish  or  purplish.  Pods 
necklace-shaped,  with  a  long  beak.  A  common  weed  eastward, 
introduced  from  Europe. 

VI.     NASTURTIUM,  R.  Br. 

Annual  or  biennial,  mostly  aquatic  plants.  Stems  erect  or 
diffuse,  often  widely  branching.  Leaves  simple,  pinnately 
lobed.  Flowers  small,  white  or  yellow.  Sepals  spreading. 
Stamens  1-6.  Pod  short  and  broad  or  nearly  linear.  Seeds 
numerous  in  2  rows  in  each  cell.* 

1.  N.  officinale,  R.  Br.      WATERCRESS.     Aquatic  herbs.      Stems 
smooth,  diffuse,  rooting  at  the  joints.     Leaves  with  3-9  rounded, 
pinnate   lobes,    the    terminal    lobe    much    the    largest.     Racemes 
elongating  in  fruit.     Petals  white,  twice  the  length  of  the  sepals. 
Pods  linear,  £- ^  in.  long,  on  slender,  spreading  pedicels.     In  ditches 
and  slow  streams.     Often  used  for  salad.* 

2.  N.  palustre,  DC.     YELLOW  WATERCRESS.     Annual   or   bien- 
nial.    Stem   erect,   branched,    slightly  downy.     Leaves   irregularly 


DICOTYLEDONOUS   PLANTS  97 

lyrate,  the  lower  petioled,  the  upper  sessile.  Flowers  small.  Petals 
yellow.  Pods  linear,  spreading,  longer  than  the  pedicels.  In  wet 
places.* 

VII.    CARDAMINE,  Tourn. 

Annual  or  perennial.  Rootstock  often  scaly  or  bulb-bear- 
ing. Stem  erect  or  ascending,  usually  smooth.  Leaves 
more  or  less  divided.  Flowers  in  terminal  racemes,  white  or 
purple.  Petals  rather  large.  Stamens  6.  Fruit  a  linear 
flattened  pod.  Seeds  several,  in  a  single  row  in  each  cell.* 

1.  C.  rhomboidea,  DC.    BULBOUS  CRESS.    Perennial.    Root  tuber- 
ous.    Stem  simple,  erect,  smooth,    without  runners,  9-18  in.  tall. 
Lower  leaves  long-petioled,  ovate,  orbicular  or  heart-shaped,  often 
angled  or  toothed,  the  upper  short-petioled  or  sessile,  lanceolate  or 
oblong,  toothed  or  entire.      Pedicels  £-1    in.  long.      Petals  white, 
±-%  in.  long.     Pod  erect,  linear-lanceolate,  tipped  by  the  persistent 
style.     Seeds  round-oval.     Cool,  wet  places.* 

2.  C.  pennsylvanica,  Muhl.    BITTER  CRESS.   Annual.   Stem  slender, 
erect,  simple,  or  with  a  few  slender  branches,  6-15  in.  tall.     Leaves 
mostly  in  a  cluster  at  the  base  of  the  stem,  pinnately  divided,  the 
terminal  lobe  roundish,  the  lateral  lobes  narrower,  somewhat  hairy 
above,  stem-leaves   nearly   linear.      Flowers   small.     Petals   white, 
longer  than  the  sepals.     Stamens  4.     Pods  linear,  erect  on  erect 
pedicels,  about  1  in.  long.     Seeds  oval.     In  wet  places.* 


Vffl.    DENTARIA,  Tourn. 

Stems  naked  below,  2-3-leaved  above,  from  a  thickish, 
more  or  less  knotted  or  interrupted  rootstock.  Flowers 
rather  large,  in  early  spring.  Pod  lance-linear,  flattish.  Seeds 
in  1  row,  wingless,  seedstalks  broad  and  flat. 

1.  D.  diphylla,  L.     TWO-LEAVED  TOOTH  WORT,   PEPPER    ROOT, 
CRINKLE  ROOT.     Rootstock  long,  often  branched,  toothed,  eatable, 
with    a  flavor   like   that    of  cress  or  radish.     Stem-leaves  2,  close 
together,  each  composed  of  3  ovate-diamond-shaped  and  toothed  or 
crenate  leaflets  ;  the  root-leaf  like  the  stem-leaves.     Flowers  white. 
Damp  woods. 

2.  D.  laciniata,  Muhl.     CROW'S  FOOT.     Rootstock  short,  necklace- 
like.     Stern-leaves  3-parted  ;  root-leaf  often  absent.     Flowers  white 
or  rose-color.     Woods. 


98  FOUNDATIONS   OF  BOTANY 


IX.    CAPSELLA,  Medic. 

Annual.  Stem  erect,  downy,  with  branched  hairs.  Racemes 
terminal,  becoming  elongated  in  fruit.  Flowers  small,  white. 
Pod  obcordate  or  triangular,  flattened  contrary  to  the  parti- 
tion, shorter  than  the  spreading  pedicel.* 

1.  C.  Bursa-pastoris,  Moench.  SHEPHERD'S  PURSE.  Root  long  and 
straight.  Stem  branching  above,  downy  below,  smooth  above. 
Lower  leaves  forming  a  rosette  at  the  base  of  the  stem,  irregularly 
lobed  or  pinnately  cut,  stem-leaves  lanceolate,  clasping,  toothed  or 
entire.  Sepals  downy,  about  ^  as  long  as  the  petals.  Pod  trian- 
gular, notched,  or  cordate  at  the  apex.  Seeds  several  in  each  cell. 
A  common  weed.* 

X.    ARABIS,  L. 

Annual  or  perennial  herbs,  smooth  or  with  forked  or  star- 
shaped  hairs.  Radical  leaves  spatulate  ;  stem-leaves  sessile. 
Flowers  usually  white.  Petals  entire,  usually  with  claws. 
Pods  linear,  flattened.  Seeds  often  margined  or  winged. 

1.  A.  hirsuta,  Scop.     A  rough-hairy,  erect,  leafy-stemmed  bien- 
nial, 1-2  ft.  high.     Leaves  simple  ;  stem-leaves  oblong  or  lanceolate, 
entire  or  toothed,  somewhat  clasping,  often  with  an  arrow-shaped 
base.     Flowers   small,  greenish-white,  the  petals  somewhat   longer 
than  the  sepals.     Pods  and  pedicels  upright.     Style  almost  wanting. 
Seeds  roundish,  somewhat  wing-margined.     Rocks,  N. 

2.  A.  laevigata,  Poir.     A  smooth,  leafy-stemmed  biennial  1-2  ft. 
high,    covered   with    a   bloom.     Stem-leaves    lance-linear,    clasping. 
Flowers  small  and  whitish,  the  petals  hardly  longer  than  the  sepals. 
Pods  2-3  in.  long,  flattened,  spreading,  and  recurved.     Seeds  broadly 
winged.     Rocks. 

3.  A.  canadensis,    L.     SICKLE  POD.     An  upright,  leafy-stemmed 
biennial,  2-3  ft.  high,  simple  or  slightly  branching  above,  some- 
times   slightly    hairy   at    the   base.     Stem-leaves    sessile,    oblong- 
lanceolate,  pointed  at  both  ends,  downy,    the  lower  ones  toothed. 
Flowers  small,  whitish,  the  petals  twice  as  long  as  the  sepals.     Pods 
scythe-shaped,  much  flattened,  hanging  from  hairy  pedicels.     Seeds 
broadly  winged.     Rocky  hillsides. 

XI.    LOBULARIA,  Desv.     (ALYSSUM,  L.) 

Perennial,  though  usually  growing  as  an  annual.  Stems 
branching,  diffuse;  brandies  slender.  Leaves  small,  entire, 


DICOTYLEDONOUS   PLANTS  99 

downy,  with  forked  hairs.  Flowers  small,  white,  in  numerous 
terminal  racemes.  Petals  obovate,  entire,  twice  as  long  as 
the  sepals.  Filaments  enlarged  below.  Pod  round,  com- 
pressed. Seeds  1  in  each  cell.* 

1.  L.  maritima,  Desv.  SWEET  ALYSSUM.  Stem  weak,  diffuse, 
ascending,  minutely  downy.  Lower  leaves  narrowed  into  a  petiole, 
the  upper  sessile.  Racemes  erect,  many-flowered.  Flowers  fra- 
grant, pedicels  ascending.  Pod  often  pointed.  Common  in  culti- 
vation and  often  run  wild.* 

XH.    MATTHIOLA,  R.  Br. 

Herbaceous  or  shrubby  oriental  plants,  covered  with  a  down 
composed  of  star-shaped  hairs.  Flowers  in  showy  racemes 
of  many  colors,  ranging  from  white  to  crimson.  Stigmas 
large  and  spreading.  Pods  nearly  cylindrical,  except  for  a 
prominent  midrib  on  each  valve. 

1.  M.  incana,  Br.  COMMON  STOCK,  GILLYFLOWER.  Biennial  or 
perennial,  with  somewhat  woody  stems.  Cultivated  in  greenhouses 
and  gardens. 

40.  CAPP  ARID  ACE  JE.     CAPER  FAMILY. 

Herbs  (when  growing  in  cool  temperate  regions),  with  bit- 
ter or  nauseous  juice.  Leaves  alternate,  usually  palmately 
compound.  Flowers  often  irregular,  usually  perfect.  Sepals 
4-8.  Petals  4  or  wanting.  Stamens  6  or  more.  Ovary  and 
pod  1-celled,  with  2  rows  of  ovules.  Seeds  kidney-shaped. 

I.    POLANISIA,  Raf. 

Ill-smelling  annual  plants  covered  with  glandular  or 
clammy  hairs.  Sepals  distinct,  spreading.  Petals  with 
claws,  notched  at  the  tip.  Stamens  8-32,  of  various  lengths. 
Receptacle  not  lengthened.  Pod  linear  or  oblong,  rather 
large,  many-seeded. 

1.  P.  graveolens,  Raf.  A  very  strong-scented,  leafy,  branching 
herb,  6-15  in.  high.  Leaves  with  3  oblong  leaflets.  Flowers  small, 
pinkish  and  yellowish-white,  in  the  axils  of  leafy  bracts,  in  terminal 
racemes.  Stamens  8-12,  not  much  longer  than  the  petals.  Pod 
about  2  in.  long,  slightly  stalked.  Gravelly  banks. 


100  FOUNDATIONS   OF   BOTANY 


H.    CLEOME,  L. 

Mostly  annual  herbs  ;  stems  branched.  Leaves  petioled, 
simple,  or  with  3-7  entire  or  serrate  leaflets.  Flowers  in 
bracted  racemes.  Sepals  4,  often  persistent.  Petals  4,  often 
long-clawed,  nearly  equal,  entire.  Stamens  6,  filaments 
thread-like,  usually  projecting  much,  but  sometimes  1-3  much 
shorter  than  the  others,  inserted  on  the  short  receptacle. 
Ovary  on  a  short  stalk  with  a  small  gland  at  its  base.  Fruit 
a  slender  capsule  on  an  elongated  stalk.* 

1.  C.  integrifolia,  Ton.  and  Gr.     ROCKY  MOUNTAIN  BEE  PLANT. 

A  smooth  plant  2  ft.  or  more  high.  Leaves  with  3  leaflets.  Flowers 
pink,  showy,  in  leafy-bracted  racemes.  Pod  oblong  to  linear,  1-2  in. 
long.  Cultivated  as  an  ornamental  plant  and  also  for  bees.  Common 
in  a  wild  condition  "W. 


41.   RESEDACE.3L.     MIGNONETTE  FAMILY. 

Annual  or  perennial  herbs,  rarely  shrubs.  Leaves  alter- 
nate, simple  or  pinnately  cut.  Flowers  racemed  or  spiked, 
bracted.  Calyx  4-7,  parted,  often  irregular.  Petals  4-7, 
hypogynous,  often  unequal  and  cleft  or  notched.  Stamens 
usually  many,  borne  on  a  large  one-sided  hypogynous  disk. 
Ovary  of  2-6  carpels,  which  are  more  or  less  united  into  a 
single  1-celled,  many-seeded,  several-lobed,  or  horned  pistil, 
which  opens  at  the  top  before  the  seeds  ripen. 

RESEDA,  Tourn. 

Annual ;  stems  diffuse,  widely  branched.  Leaves  sessile, 
entire  or  lobed,  smooth.  Flowers  in  close  racemes  or  spikes. 
Petals  4-7,  toothed  or  cleft.  Stamens  8-30,  inserted  at  one 
side  of  the  flower.  Capsule  3-6-lobed.* 

1.  R.  odorata,  L.  MIGNONETTE.  Stem  widely  diffuse,  6-12  in. 
high,  smooth.  Leaves  wedge-shaped,  entire  or  3-lobed.  Flowers 
small,  greenish-yellow,  very  fragrant.  Petals  deeply  7-13-cleft. 
Often  cultivated.  From  Egypt.* 


DICOTYLEDONOUS   PLANTS  101 


42.    SARRACENIACE^).     PITCHER-PLANT  FAMILY. 

Perennial,  stemless,  marsh,  herbs.  Leaves  tubular  or 
trumpet-shaped.  Flowers  single,  nodding,  on  a  naked  or 
bracted  scape.  Sepals  4-5,  colored,  persistent.  Petals  5, 
deciduous,  or  sometimes  wanting.  Stamens  numerous.  Pistil 
compound,  5-celled,  many-ovuled  ;  style  terminal,  nearly  as 

broad  as  the  flower,  shield-shaped.* 

| 

SARRACENIA,  Tourn. 

Rootstock  short,  horizontal ;  scape  naked.  Leaves  trumpet- 
shaped,  with  a  wing  extending  nearly  to  the  base  and  a  broad 
blade  at  the  apex  (see  Part  II,  Ch.  XXVI)  ;  tube  hairy 
within,  with  downward-pointing,  stiff  hairs.  Calyx  3-bracted. 
Petals  obovate,  'drooping  or  incurved.  Style  umbrella-shaped, 
5-angled  ;  stigmas  at  the  hooked  angles  of  the  style  on  the 
under  surface.  Capsule  globose,  rough.  [The  tubular  leaves 
usually  contain  more  or  less  water  and  dead  insects,  the  latter 
having  been  attracted  by  a  honey-like  secretion  near  the 
opening.  For  a  full  account  of  the  structure  and  peculiar 
action  of  the  leaves,  see  Goodale's  Physiological  Botany, 
pp.  347-353.]* 

1.  S.  purpurea,  L.  SIDE-SADDLE  FLOWER.  Leaves  ascending, 
curved,  broadly  winged,  purple-veined,  4-8  in.  long;  blade  erect, 
round-cordate,  hairy  on  the  inner  side.  Scapes  12-18  in.  tall ;  flower 
deep  purple,  about  2  in.  broad.  Style  yellowish.  Mossy  swamps.* 


43.    SAXIFRAGACE^E.     SAXIFRAGE  FAMILY. 

Herbs  or  shrubs.  Leaves  alternate  or  opposite,  generally 
without  stipules.  Sepals  4  or  5,  more  or  less  coherent  with 
each  other  and  adnate  to  the  ovary.  Petals  as  many  as  the 
sepals  and  alternate  with  them.  Stamens  as  many  as  the 
petals  and  alternate  with  them,  or  2-10  times  as  many. 
Ovary  usually  of  2  carpels,  united  only  at  the  base  or  more 
or  less  throughout.  Fruit  generally  a  1-2-celled  capsule, 
sometimes  a  berry.  Seeds  many,  with  endosperm. 


102  FOUNDATIONS   OF   BOTANY 


I.     SAXIFRAGA,  L. 

Herbs  with,  simple  or  palmately  cut  leaves  and  generally 
cymose  or  panicled  flowers.  Sepals  5,  more  or  less  united. 
Petals  5,  entire,  inserted  on  the  calyx-tube.  Stamens  10. 
Capsule  consisting  of  2  (sometimes  more)  ovaries,  united  at 
the  base,  separate  and  diverging  above. 

1.  S.    virginiensis,    Michx.      EARLY    SAXIFRAGE,    MAYFLOWER. 
Perennial.     Stemless,  with  a  cluster  of  spatulate,  obovate,  or  wedge- 
shaped  root-leaves  and  a  scape  3-9  in.  high,  which  bears  a  dense 
cluster  of  small  white  flowers,  becoming  at  length  a  panicled  cyme. 
Petals  white,  oblong,  much  longer  than  the  calyx.     Rocks  and  dry 
hillsides  N. 

2.  S.    pennsylvanica,     L.       SWAMP     SAXIFRAGE.       Perennial. 
Leaves  4-8    in.  long,  oblong-lanceolate  and  tapering  to   the   base, 
slightly  toothed.     Scape  1-2  ft.  high,  bearing  an  oblong  cluster  of 
small  greenish  flowers,  at  length  diffusely  panicled.     Petals  green- 
ish-yellow (rarely  crimson),  linear-lanceolate,  hardly  longer  than  the 
calyx-lobes.     Boggy  ground. 

II.     TIARELLA,  L. 

Perennial.  Flowers  white,  in  racemes.  Calyx  white, 
5-parted,  nearly  free  from  the  ovary.  Corolla  of  5  very  nar- 
row petals,  with  slender  claws,  alternating  with  the  calyx- 
lobes.  Stamens  10,  springing  from  the  calyx-tube  arid 
extending  outside  the  flower.  Styles  2,  long  and  slender. 
Ovary  1-celled,  2-beaked.  In  fruit  one  of  the  carpels  grows 
to  be  much  larger  than  the  other,  thus  making  up  the  main 
bulk  of  the  thin,  dry  pod,  which  has  a  few  seeds  attached 
near  the  bottom. 

1.  T.  cordifolia,  L.  FALSE  MITRE-WORT.  Stem  5-12  in.  high, 
usually  leafless,  sometimes  with  1  or  2  leaves.  Rootstock  bearing 
runners  in  summer.  Leaves  heart-shaped,  sharply  lobed,  the  lobes 
with  acute  or  mucronate  teeth,  somewhat  hairy  above,  downy 
beneath.  Raceme  short  and  simple.  Rocky  woods,  especially  N. 


IH.    MITELLA,  Tourn. 

Delicate  perennial  herbs.     Flowers  small,  pretty,  in  a  sim- 
ple raceme  or  spike.     Calyx  5-cleft,  adnate  to  the  base  of  the 


DICOTYLEDONOUS   PLANTS  103 

ovary.  Petals  5,  cut-fringed,  inserted  on  the  throat  of  the 
calyx-tube.  Stamens  5  or  10,  not  projecting  from  the  calyx- 
tube.  Styles  2,  very  short.  Ovary  and  pod  2-beaked, 
globular,  1-celled. 

1.  M.  diphylla,  L.  TWO-LEAVED  BISHOP'S  CAP,  FRINGE  CUP, 
FAIRY  CUP.  Stemless,  with  long-petioled,  roundish-cordate  root- 
leaves,  and  a  scape  about  1  ft.  high,  bearing  2  opposite,  nearly  ses- 
sile leaves.  Flowers  many,  racemed,  white.  Woods. 

IV.    HEUCHERA,  L. 

Perennials  with  a  tall  scape  and  roundish,  heart-shaped 
radical  leaves.  Flowers  rather  small,  greenish  or  purplish, 
in  a  long  panicle.  Calyx  5-cleft,  the  tube  below  adnate  to  the 
ovary.  Petals  5,  small,  spatulate,  inserted  with  the  5  sta- 
mens on  the  margin  of  the  calyx-tube.  Capsule  1-celled, 
2-beaked,  splitting  open  between  the  beaks. 

1.  H.  americana,  L.  COMMON  ALUM  ROOT.  Scapes  2-4  ft.  high, 
rather  slender,  often  several  from  the  same  root,  hairy  and  glandu- 
lar. Radical  leaves  large  and  long-petioled,  abundant,  somewhat 
7-lobed.  Flowers  whitish  with  a  tinge  of  purple,  in  a  loose  panicle. 
Stamens  projecting  considerably  outside  the  flower,  their  stamens 
of  a  bright  terra  cotta  color.  The  root  is  very  astringent  and  is 
somewhat  used  as  a  home  remedy.  Shaded  banks,  fence  rows,  and 
thickets  ;  common  W. 

V.    PHILADELPHUS,  L. 

Shrubs.  Leaves  simple,  opposite,  3-5-ribbed,  petioled, 
without  stipules.  Flowers  solitary  or  in  cymes,  large,  white. 
Calyx-tube  top-shaped,  adnate  to  the  ovary,  the  limb  4-5- 
parted,  persistent.  Petals  4-5,  rounded  or  obovate.  Stamens 
20-40,  shorter  than  the  petals.  Ovary  3-5-celled,  many- 
seeded  ;  styles  3-5,  more  or  less  united.* 

1.  P.    grandiflorus,  Willd.     LARGE-FLOWERED  SYRINGA.     Shrub, 
6-10  ft.  high;    branches   downy.      Leaves  ovate  or   ovate-oblong, 
taper-pointed,  sharply  serrate,  downy,  3-ribbed.     Flowers  solitary  or 
2—3    together,    white,   1^-2    in.  broad,   not   fragrant.      Calyx-lobes 
ovate,  taper-pointed,  about   twice    as   long   as  the   tube.     On   low 
ground,  S.,  and  cultivated.* 

2.  P.  coronarius,  L.     GARDEN  SYRINGA.     Shrub,  8-10  ft.  high. 
Leaves  oval  or  ovate,  obtuse  at  the  base,  acute  at  the  apex,  remotely 


104  FOUNDATIONS   OF  BOTANY 

toothed,  smooth  above,  downy  beneath.  Flowers  in  terminal 
racemes,  creamy  white,  1-1^  in-  wide,  very  fragrant.  Calyx-lobes 
ovate,  acute,  longer  than  the  tube.  Common  in  cultivation.* 


VI.    DEUTZIA,  Thunb. 

Shrubs  with  simple,  opposite  leaves,  without  stipules. 
Flowers  all  perfect  and  alike,  racemed  or  panicled,  showy. 
Calyx-lobes  5.  Petals  5.  Stamens  10,  5  long  and  5  short  ; 
filaments  flat  and  3-pronged,  the  middle  prong  bearing  an 
anther.  Styles  3-5,  slender.  Pod  3-5-celled. 

1.  D.  gracilis,  Sieb.  and  Zucc.  About  2  ft.  high,  loosely  spreading. 
Leaves  ovate-lanceolate,  sharply  serrate,  smooth.  Flowers  white, 
very  numerous.  Cultivated  from  Japan,  often  in  greenhouses. 


VH.    RIBES,  L. 

Shrubs.  Leaves  palmately  veined  and  lobed,  sometimes 
with  stipules.  Calyx-tube  egg-shaped,  adnate  to  the  1-celled 
ovary,  its  5  lobes  usually  colored  like  the  petals.  Petals  5, 
small,  generally  inserted  on  the  throat  of  the  calyx-tube. 
Stamens  5,  inserted  with  the  petals.  Styles  2.  Ovary 
1-celled,  with  2  placentse  on  its  walls,  becoming  in  fruit  a 
pulpy  (usually  eatable)  berry. 

1.  R.  rotundifolium,  Michx.     SMOOTH  WILD  GOOSEBERRY.  Spines 
few  and  short,  prickles  few  or  absent.     Leaves  roundish,  lobed,  with 
the  lobes  crenate-dentate,  often  downy.     Peduncles  slender  ;  flowers 
inconspicuous.     Calyx-lobes  reflexed.     Styles  and  stamens  projecting 
decidedly  from  the  calyx-tube.     Berries  smooth. 

2.  R.  Cynosbati,  L.     PRICKLY  WILD    GOOSEBERRY.     Spines   in 
pairs.    Leaves  long-petioled,  downy,  heart-shaped,  cut-dentate.     The 
single  style  and  the  stamens  not  projecting  from  the  calyx-tube. 
Berries  generally  prickly,  brownish-purple,  pleasant-flavored. 

3.  R.  rubrum,  L.     RED  CURRANT.     Stems  more  or  less  reclining. 
Leaves  somewhat  heart-shaped,  obtusely  3-5-lobed.    Racemes  droop- 
ing.    Limb  of  the  calyx  wheel-shaped.     Berries  acid,  eatable,  red 
or  light  amber-colored.     Cultivated  from  Europe,  also  a  variety  wild 
in  the  northern  United  States. 

4.  R.  aureum,  Pursh.     GOLDEN  CURRANT,  FLOWERING  C.,  MIS- 
SOURI C.,  CLOVE  C.     A  much  taller  shrub  than  the  common  red 
currant.     Leaves  3-lobed,  toothed.     Racemes  short  and  loose.    Tube 


DICOTYLEDONOUS   PLANTS  105 

of  the   yellow   calyx  much   longer  than   its  limb.      Flowers   very 
fragrant.     Fruit  brownish-black,  barely  eatable. 


44.   PLATANACE^.     SYCAMORE  FAMILY. 

Trees  ;  with  simple,  alternate,  petioled  leaves  with  stipules, 
the  bases  of  the  petioles  covering  the  buds.  Flowers  monoe- 
cious, in  axillary,  long-peduncled,  globose  heads.  Calyx  and 
corolla  very  inconspicuous,  each  consisting  of  3-8  minute 
scales,  or  wanting.  Stamens  as  many  as  the  sepals  and 
opposite  them.  Pistils  several,  inversely  conical,  hairy  at 
the  base,  styles  long.  Capsules  1-seeded.* 

PLATANUS,  L. 

Characters  of  the  family. 

1.  P.  occidentalis,  L.  SYCAMORE,  BUTTONWOOD.  A  large  tree, 
bark  light-colored,  smooth,  peeling  off  in  large,  thin  plates.  Leaves 
large,  round  heart-shaped,  angularly  lobed  and  toothed,  densely 
white-woolly  when  young,  becoming  smooth  with  age ;  stipules 
large,  toothed.  Fruit  in  a  globular,  drooping  head,  which  remains 
on  the  tree  through  the  winter,  dropping  the  seeds  very  slowly. 
Common  on  river  banks  and  in  swampy  woods.* 

45.   ROSACEJE.     ROSE  FAMILY. 

Herbs,  shrubs,  or  trees.  Leaves  alternate  or  rarely  oppo- 
site, simple  or  compound,  with  stipules.  Calyx  5-lobed. 
Petals  5,  rarely  wanting,  inserted  with  the  stamens  on  the 
edge  of  a  disk  that  lines  the  calyx-tube.  Stamens  many, 
rarely  1  or  few.  Carpels  1  or  more,  distinct  or  coherent,  free 
or  adnate  to  the  calyx-tube.  Fruit  a  pome,  a  stone-fruit  or 
group  of  stone-fruits,  or  1-several  akenes  or  follicles,  rarely 
a  berry  or  capsule.  The  relation  of  the  parts  of  the  flower 
to  each  other  and  to  the  receptacle  is  shown  in  Fig.  13. 


106 


FOUNDATIONS   OF   BOTANY 


Ripe  carpels  not  enclosed  within  the  calyx-tube. 

1.  Fruit  dry. 

(a)  Carpels  1-5,  inflated.  Physocarpus,  I. 

(b)  Pods  5-8,  not  inflated.  Spiraea,  IT. 

(c)  Akenes  2-6,  styles  not  lengthening  after  flowering. 

Waldsteinia,  VIII. 

(e?)  Akenes  many,  on  a   dry  receptacle.     Styles  not  length- 
ening. Potentilla,  X, 
(e)  Akenes  many,  on  a  dry  receptacle.     Styles  lengthening- 
after  flowering,  forming  tails  to  the  akenes. 

Geum.,  XI. 

2.  Fruit  fleshy. 

(a)  Akenes  several-many,  becoming  little  stone-fruits. 

Rubus,  VII. 

(b)  Akenes   many,    dry    on    ripening,    on    a   fleshy,    eatable 

receptacle.  Fragaria,  IX. 

(c)  Pistil  solitary,  becoming  a  stone-fruit.          Prunus,  XIII. 


A  B  C      . 

FIG.  13.  —  Pistils  in  the  Rose  Family. 
A,  Prunus-type  ;  B,  Potentilla-type  ;  C,  Rosa-type,  c,  calyx,  o,  ovary. 

B. 

Ripe  carpels  enclosed  ivithin  the  calyx-tube. 
1.  Fruit  a  pome. 

(a)   Carpels  more  than  2-seeded ;  seeds  covered  with  a  muci- 
laginous pulp.     Fruit  5-celled.  Cydonia,  III. 


DICOTYLEDONOUS   PLANTS  107 

(6)  Carpels  2-seeded  (except  in  some  cultivated  varieties)  ; 

seeds  without  pulp.     Fruit  5-celled.  Pyrus,  IV. 

(c)  Carpels  2-seeded  ;  fruit  10-celled.  Amelanchier,  V. 

2.  Fruit  not  evidently  a  pome  or  not  at  all  so. 

(a)  Trees  or  shrubs.    Fruit  appearing  like  a  stone-fruit,  with 
a  stone  usually  of  2-5  bony  1-seeded  carpels  united. 

Cratsegus,  VI. 

(6)  Herbs.     Fruit  consisting  of  numerous  very  small  akenes 

collected  on  a  fleshy,  eatable  receptacle.     Fragaria,  IX. 

(c)  Trees  or  shrubs.     Fruit  a  simple   stone-fruit  (plum  or 

cherry).  Prunus,  XIII. 

I.    PHYSOCARPUS,  Maxim. 

Shrubs.  Leaves  simple,  palmately  veined  and  lobed,  pet- 
ioled.  Flowers  white,  in  terminal  corymbs.  Calyx  spreading, 
5-lobed.  Petals  5.  Stamens  numerous.  Pistils  1-5,  short- 
stalked,  stigma  terminal ;  ovaries  becoming  inflated  at  matu- 
rity, 2-4-seeded,  splitting  open.* 

1.  P.  opulifolius,  Maxim.  NINEBARK.  A  spreading  shrub  3-6  ft. 
high,  the  old  bark  separating  into  thin  strips.  Leaves  petioled, 
broadly  ovate  or  rounded,  often  heart-shaped,  3-lobed,  the  lobes  doubly 
crenate-serrate  ;  stipules  deciduous.  Corymbs  terminal,  peduncled, 
nearly  globose,  downy,  many-flowered.  Pedicels,  and  calyx  nearly 
smooth.  Follicles  3-5,  much  longer  than  the  calyx,  smooth  and 
shining,  obliquely  tipped  by  the  persistent  style.  Banks  of  streams, 
and  often  cultivated.* 

H.    SPIREA,  L. 

Shrubs  with  simple  leaves.  Flowers  perfect,  in  terminal 
or  axillary  racemes  or  panicles.  Calyx  5-cleft,  persistent. 
Petals  5.  Stamens  numerous.  Pistils  usually  f>,  free  from 
the  calyx  and  alternate  with  its  lobes.  Follicles  not  inflated, 
2-several-seeded.* 

1.  S>  salicifolia,  L.  WILLOW-LEAFED  SPIREA.  Shrubs  2-5  ft. 
high,  branches  smooth  ;  leaves  lanceolate  to  oblong-ovate,  smooth 
or  nearly  so,  sharply  serrate,  base  usually  wedge-shaped,  pale  beneath  ; 
stipules  deciduous ;  flowers  white  or  pink,  panicle  dense-flowered ; 
follicles  smooth.  On  low  ground.* 


108  FOUNDATIONS   OF   BOTANY 

2.  S.   reevesiana,  Card.     BRIDAL  WREATH.     Shrubs  2-4  ft.  tall ; 
branches  long,   slender,   and  spreading  ;  leaves  lanceolate,  serrate, 
sometimes  3-lobed  or  pinnatifid,  with  a  bloom  beneath  ;  flowers  white 
or  pinkish,  in    axillary  racemes  or  corymbs,   often  forming  long 
wreaths ;  follicles  smooth.     Cultivated  from  Europe. 

3.  S.  tomentosa,  L.     HARDHACK.     Erect  shrubs  ;  stems  densely 
downy,   usually  simple;    leaves    simple,    ovate    or   oblong,    serrate, 
densely  rusty  downy  below,  smooth  and  dark  green  above ;  flowers 
small,  pink  or  purple,  in  a  close  panicle ;  follicles  5,  densely  downy, 
several-seeded.    On  low  ground  S.,  and  along  fence-rows  and  in  pas- 
tures N.,  where  it  is  a  troublesome  weed.* 

III.  CYDONIA. 

Trees  or  shrubs.  Leaves  simple,  toothed  or  lobed,  stipules 
deciduous.  Flowers  usually  solitary,  white  or  pink.  Calyx- 
tube  urn-shaped,  adnate  to  the  ovary,  5-lobed,  lobes  acute, 
spreading,  persistent.  Petals  5.  Stamens  numerous,  inserted 
with  the  petals  on  the  calyx-tube.  Styles  2-5,  mostly  5, 
united  at  the  base.  Ovary  5-celled,  seeds  many  in  each  cell. 
Fruit  a  pome,  globose,  usually  depressed  or  hollowed  at  the* 
extremities,  flesh  without  hard  grains.* 

1.  C.  vulgaris,  Pers.     QUINCE.     Shrub    6-12   ft.   high.      Leaves 
oblong-ovate,  acute  at  the  apex,  obtuse  at  the  base,  entire,  downy 
below.     Flowers  large,  white  or  pink.     Fruit  ovoid,  downy.     Cul- 
tivated.* 

2.  C.    japonica,   Pers.      JAPAN    QUINCE.      A   widely  branching 
shrub,  3-6  ft.  high,  branches  with  numerous  straight  spines.    Leaves 
ovate-lanceolate,  acute  at  each  end,  smooth  and  shining,  serrulate ; 
stipules  conspicuous,  kidney-shaped.     Flowers  in  nearly  sessile  axil- 
lary clusters,  bright  scarlet.    Fruit  globose.    Common  in  cultivation.* 

IV.  PYRUS,  L. 

Trees.  Leaves  simple,  stipules  small,  deciduous.  Flowers 
in  cymes,  large,  white  or  pink.  Calyx  urn-shaped,  adnate  to 
the  ovary,  5-cleft,  its  lobes  acute.  Petals  rounded,  short- 
clawed.  Stamens  numerous,  borne  with  the  petals  on  the 
calyx-tube.  Styles  5,  distinct  or  slightly  united  at  the  base. 
Fruit  a  pome,  with  about  2  seeds  in  each  carpel.* 

1.  P.  communis,  L.  PEAR.  A  tree,  often  very  large,  head  usually 
pyramidal  j  branches  often  thorny.  Leaves  thick  and  leathery, 


DICOTYLEDONOUS  PLANTS  109 

ovate  or  oval,  acute,  finely  serrate  or  entire,  downy  when  young, 
becoming  smooth  with  age  ;  petioles  slender.  Cymes  few— several- 
flowered,  terminal,  and  at  the  ends  of  "fruit  spurs"  grown  the 
previous  season.  Flowers  white.  Styles  not  united.  Fruit  obovoid, 
with  hard  gritty  grains  near  the  core.  A  European  and  Asiatic 
tree  common  in  cultivation.* 

2.  P.  Malus.      APPLE.      A  tree  with  a  rounded  top  and  dark- 
colored  bark.     Leaves  oval  or  ovate,  obtuse  or  pointed,  dentate  or 
nearly  entire,  rounded  at  the  base,  smooth  above,  downy  beneath. 
Cymes  few— many-flowered.     Flowers  large,  white  or  pink.     Calyx 
downy.     Fruit  depressed-globose  to  ovoid,  hollowed  at  the  base  and 
usually  at  the  apex.     Cultivated  from   Europe  and  often  running 
wild  .in  old  pastures,  etc.,  E.* 

3.  P.   coronaria,   L.     AMERICAN    CRAB    APPLE.      A   small  tree 
with  smooth  bark.     Leaves  triangular  or  oval-lanceolate,  acutish  or 
rounded  or  a  little  heart-shaped  at  the  base,  cut-serrate  and  often 
somewhat   3-lobed,  slender-petioled,  soon   smooth.      Flowers  large, 
few  in  a  cluster,  pale  rose-color,  very  sweet-scented.     Fruit  bright 
green,  turning  yellowish,  sometimes  1£  in.  in  diameter,  flattened  at 
right  angles  to  the  pedicels,  very  fragrant.     Glades,  W.  N.  Y.,  West 
and  South. 

4.  P.  angustifolia,  Ait.    NARROW-LEAVED  CRAB  APPLE.    A  small 
tree  with  smooth,  light  gray  bark.     Leaves  lanceolate  or  oblong, 
serrate,    downy    when    young,    acute    at    the   base,    short-petioled. 
Corymbs  few-flowered.     Flowers  pink,  fragrant,  about  1  in.  broad. 
Styles  smooth,  distinct.     Fruit  nearly  globose,  about  f  in.  in  diame- 
ter, very  sour.     In  open  woods,  Penn.,  W.  and  S.* 

5.  P.  arbutifolia,  L.  f.     CHOKEBERRY,  CHOKE  PEAR,  DOGBERRY. 
A  shrub  5-8  ft.  high.     Leaves  oblong  or  oblanceolate,  finely  serrate, 
downy  beneath,    short-petioled.      Flowers   in   a   downy   compound 
cyme,  small,  white  or  reddish.    Fruit  pear-shaped  or  nearly  globular, 
not  larger  than  a  currant,  very  dark  purple,  dry  and  puckery.    There 
is  also  a  smooth-leaved  variety  with  black  fruit.     Swamps  and  damp 
thickets,  especially  N.  E. 

6.  P.  americana,  DC.    AMERICAN  MOUNTAIN  ASH.     A  tall  shrub 
or  small  tree.    Leaves  odd-pinnate.    Leaflets  oblong-lanceolate,  taper- 
pointed,  sharply  serrate,  smooth,  bright  green.    Flowers  small,  white, 
in  large,  flat,  compound  cymes.      Fruit  bright  scarlet,  not  larger 
than  currants.     Common  N.  and  often  cultivated. 

7.  P.  Aucuparia,  Gaertn.     EUROPEAN  MOUNTAIN  ASH  OR  ROWAN 
TREE.     Larger  than  No.  6.     Leaflets  paler,  downy  beneath.     Fruit 
larger,  about  £  in.  in  diameter.     Cultivated  from  Europe. 


110  FOUNDATIONS   OF   BOTANY 


V.    AMELANCHIER,  Medic. 

Shrubs  or  small  trees  with  smooth  gray  bark.  Leaves 
simple,  sharply  serrate,  petioled.  Flowers  white,  in  racemes. 
Calyx-tube  5-cleft,  adnate  to  the  ovary.  Petals  oblong. 
Styles  5,  united  below.  Ovary  5-celled,  2  ovules  in  each  cell, 
often  only  1  maturing.  Fruit  small,  berry-like.* 

1.  A.  canadensis,  Torr.  and  Gr.  SERVICE  BERRY,  JUNE  BERRY, 
SHAD  BUSH,  SUGAR  PLUM,  SUGAR  PEAR,  WILD  PEAR.  A  small 
tree,  branches  downy  when  young,  soon  becoming  smooth.  Leaves 
ovate  to  elliptical,  finely  and  sharply  serrate,  acute  at  the  apex, 
usually  obtuse  or  cordate  at  the  base.  Racemes  slender,  many- 
flowered,  appearing  before  or  with  the  leaves.  Flowers  showy. 
Petals  4  or  5  times  the  length  of  the  smooth  sepals.  Fruit  globose, 
dark  red,  edible.  In  rich  woods  ;  extremely  variable  in  height,  and 
in  shape  of  leaves.* 

VI.    CRATJEGUS,  L. 

Shrubs  or  small,  trees,  mostly  with  numerous  strong  spines, 
wood  very  hard.  Leaves  serrate,  lobed  or  deeply  incised, 
petioled.  Flowers  white  or  pink,  in  terminal  corymbs  or 
sometimes  solitary.  Calyx-tube  urn-shaped,  5-cleft,  the  limb 
persistent.  Petals  round.  Stamens  few  or  many.  Styles 
1-5,  distinct ;  ovules  1  in  each  cell.  Fruit  a  small  pome  with 
bony  carpels.*  [The  species  are  hard  to  distinguish  and  are 
not  very  perfectly  denned.  At  present  the  genus  is  under- 
going a  careful  revision  by  Professor  C.  S.  Sargent.] 

1.  C.  coccinea,  L.    SCARLET-FRUITED  THORN,  RED  HAW.    A  tall 
shrub  or  small  tree,  with  smooth,  reddish  branches,  but  the  young 
shoots  downy.     Leaves  thin,   roundish-ovate,  cut-lobed  or  sharply 
toothed,  slender-petioled.     Flowers  large,  in  a  many-flowered  corymb. 
Fruit  bright  red,  nearly  globular  or  obovoid,  ^  in.  long. 

Var.  mollis,  Torr.  and  Gr.,  has  the  young  shoots  densely  covered 
with  down  and  fruit  twice  the  length  of  the  preceding,  sweet  and 
^edible.     Common  in  the  Mississippi  valley. 

2.  C.  tomentosa,  L.      PEAR  THORN.      A  small  tree,  the  young- 
shoots,  peduncles,  and  calyx  downy  or  soft-hairy.     Leaves  large, 
thickish,  ovate  or  ovate-oblong,  downy  beneath,  doubly  serrate  or 
cut-lobed.     Flowers  later  than  No.  1,  sometimes  1  in.  in  diameter. 
Fruit  scarlet  or  orange,  rather  less  than  1  in.  long,  edible. 

3.  C.  Crus-Galli,  L.    COCKSPUR  THORN.    Small  trees  with  spread- 
ing branches ;  spines  usually  numerous,  long  and  stout,  but  some- 


DICOTYLEDONOUS  PLANTS  111 

times  few  or  wanting.  Leaves  thick,  oval  or  obovate,  shining  above, 
paler  below,  obtuse  or  acute,  and  sharply  serrate  at  the  apex,  wedge- 
shaped  and  entire  at  the  base.  Corymbs  terminal,  many-flowered, 
smooth;  flowers  about  £  in.  wide;  styles  1-3  ;  fruit  red,  subglobose, 
^  in.  in  diameter.  Common  in  open  woods.* 

4.  C.  spathulata,  Michx.     SMALL-FRUITED  HAW.     A  small  tree, 
young  twigs    densely   downy ;    spines  1-2  in.  long  ;   leaves  small, 
spatulate,  crenate  at  the   rounded   apex,  entire  and  wedge-shaped 
below,  leathery,   smooth ;    stipules  crescent-shaped ;    corymbs  com- 
pound, many-flowered ;  flowers  small ;  calyx-lobes  very  short ;  styles 
5  ;  fruit  red,  about  the  size  of  a  small  pea.     On  river  banks.* 

5.  C.  flava,  Ait.     YELLOW  HAW.     A  small  tree  with  very  numer- 
ous spines  ;  leaves  obovate,  glandular-serrate  at  the  rounded  apex, 
cuneate    below,  downy  when  young  ;  petiole    short ;   corymbs  few- 
flowered,  slightly  downy ;  flowers  ^-f  in.  wide  ;  calyx-lobes  entire 
or  glandular-serrate  ;  styles  4-5  ;  fruit  pear-shaped,  £  in.  or  more  in 
length,  greenish-yellow.     On  sandy  soil.* 

vn.  RUBUS,  L. 

Mostly  prickly  shrubs,  producing  runners.  Leaves  alter- 
nate, simple  or  compound ;  stipules  adnate  to  the  petiole. 
Flowers  in  terminal  and  axillary  clusters,  rarely  solitary, 
white  (in  one  American  species  [No.  1]  purple  rose-color). 
Calyx  free  from  the  ovary,  with  a  broad  tube  ;  its  lobes  5, 
persistent.  Petals  5.  Stamens  many.  Carpels  many,  distinct, 
on  a  convex  receptacle.  Fruit  a  cluster  of  little  1-seeded 
stone-fruits  on  a  dry  or  somewhat  juicy  receptacle. 

A.    RASPBERRIES. 

Grains  of  the  fruity  when  ripe,  falling  off  from  the  receptacle  and 
leaving  the  latter  with  the  calyx. 

1.  Rubus  odoratus,  L.     FLOWERING  RASPBERRY  (often  wrongly 
called  MULBERRY).     Stems  shrubby  and  rather  stout,  3-5  ft.  high, 
not  prickly,  the  young  shoots,  peduncles,  and  calyx  covered  with 
sticky  glandular  hairs.     Leaves  large,  simple,  3-5-lobed.     Flowers 
showy,  rose-purple,  1-2  in.  in  diameter,  on  many-flowered  pedun- 
cles.    Fruit  flattish,  eatable.     Rather  common  E.  and  N.  and  often 
cultivated. 

2.  R.  triflorus,  Richardson.     DWARF    RASPBERRY   (also  wrongly 
known  as  MULBERRY).     A  slender  trailing  plant,  almost  entirely 
herbaceous,  not  prickly  but  sometimes  bristly.     Leaves  compound, 


112  FOUNDATIONS   OF  BOTANY 

usually  of  3  but  sometimes  of  5  thin  ovate-lanceolate,  frequently 
unsymmetrical  leaflets,  which  are  coarsely  doubly  serrate  and  often 
cleft  or  lobed,  with  a  shining  upper  surface.  Flowers  small,  on  1-3- 
flowered  peduncles.  Fruit  of  a  few  loosely  cohering  grains,  eaten 
by  children.  Common,  especially  N.t  in  hilly  woods,  often  forming 
a  dense  carpet  in  the  partial  shade  of  pines. 

3.  R.    occidentalis,  L.      BLACK    RASPBERRY.      Stems   long   and 
slender,  often  recurved  and  rooting  at  the  tips,  armed  with  weak, 
hooked  prickles.     Leaves  petioled,  3-5  ovate  leaflets,  coarsely  ser- 
rate,  white-downy   below.      Flowers   white,    in   compact   terminal 
corymbs.     Pedicels  erect  or  ascending.     Fruit  black,  hemispherical, 
separating  easily  from  the  receptacle.       Common  on  borders  of 
woods  Mo.  and  N.,  widely  cultivated.* 

4.  R.  strigosus,  Michx.     RED  RASPBERRY.     Stems  widely  branch- 
ing, biennial,  not  rooting  at  the  tips,  armed  with  weak  bristles  and 
with  a  few  hooked  prickles.     Leaves  petioled,  of  3—5  ovate  leaflets 
which  are  sharply  serrate   and   sometimes   lobed,  downy  beneath. 
Flowers  in  terminal  and  axillary  racemes  and   panicles,  pedicels 
drooping.     Fruit   hemispherical   or   conical,  red,  separating  easily 
from  the  receptacle.     Common  on  mountains  i»nd  burned  clearings. 
Iowa  and  N.  and  widely  cultivated.* 

B.   BLACKBERRIES. 

Grains  of  the  ripe  fruit  falling  from  the  calyx  along  with  the  soft, 
eatable  receptacle. 

5.  R.  nigrobaccus,  Bailey.     HIGH  BLACKBERRY.     Stem  shrubby, 
erect  or  bending,  4-10  ft.  high,  glandular-downy  above  and  with 
stout,  hooked  prickles  below.     Leaves  petioled,  of  3—7  ovate  leaflets 
which  are  acute,  irregularly  serrate,  smooth  or  soft-hairy.     Flowers 
in  terminal,  bracted  panicles.     Petals  white,  obovate,  much  longer 
than  the  taper-pointed  sepals.    Fruit  large,  black,  oblong.    Common 
in  thickets.* 

6.  R.  villosus,  Ait.      Low   BLACKBERRY,    DEWBERRY.      Stems 
shrubby,   trailing   widely,   from   3-10   ft.  long,   somewhat  prickly. 
Leaflets  usually  3,  but  sometimes  5  or  7,  ovate,  acute,  sharply  (and 
doubly)  cut-serrate,  thin.     Racemes  upright  on  the  short  branches, 
1-3-flowered.     Fruit  roundish,  of  fewer  and  larger  grains  than  No.  5, 
very  sweet  when  fully  ripe.     Common  N".,  in  stony  or  gravelly  fields. 

7.  R.  cuneifolius,  Pursh.     SAND    BLACKBERRY.     Stem    shrubby, 
erect  or  diffuse,  2-3  ft.  high  ;  prickles  straight  or  recurved.     Leaves 
petioled,    3-5-foliate  ;    leaflets  obovate,  serrate    towards  the   apex, 
wedge-shaped  towards  the  base,  rough  above,  white  downy-woolly 
beneath.      Racemes   mainly  terminal,  few-flowered.     Petals  white, 


DICOTYLEDONOUS  PLANTS  113 

longer  than  the  sepals.     Fruit  ovoid,  black,  smaller  than  the  pre- 
ceding.    Common  in  old  fields.* 

8.  R.  hispidus,  L.  Stem  trailing  or  prostrate,  often  several  feet 
in  length,  armed  with  small,  straight,  or  recurved  prickles,  and 
often  thickly  set  with  bristles.  Leaves  petioled,  mostly  of  3  leaflets  ; 
leaflets  obovate,  obtuse,  rather  coarsely  serrate.  Flowering  branches 
commonly  erect,  few-flowered,  flowers  white.  Fruit  black.  Common 
on  dry,  sandy  soil.* 

VIII.     WALDSTEINIA,  Willd. 

Stemless  perennial  herbs.  Leaves  3-5-lobed  or  divided. 
Flowers  several,  rather  small,  yellow,  on  a  bracted  scape. 
Calyx-tube  top-shaped;  the  limb  spreading,  with  sometimes 
little  bracts  alternating  with  the  lobes.  Petals  5.  Stamens 
many.  Style  2-6.  Akenes  few,  on  a  dry  receptacle. 

1.  W.  fragarioides,  Tratt.  BARREN  STRAWBERRY.  A  low  herb 
with  much  the  appearance  of  a  strawberry  plant.  Leaflets  3, 
broadly  wedge-shaped,  crenate-dentate.  Scapes  many-flowered  ;  the 
flowers  rather  pretty.  Wooded  hillsides. 


IX.    FRAGARIA,  Tourn. 

Perennial  scape-bearing  herbs,  with  runners.  Leaves  with 
3  leaflets  ;  stipules  adnate  to  the  petiole.  Flowers  (of  Ameri- 
can species)  white.  Calyx  free  from  the  ovary,  5-parted, 
5-bracted,  persistent.  Petals  5.  Stamens  many.  Carpels 
many,  on  a  convex  receptacle.  Akenes  of  the  ripe  straw- 
berry many,  very  small,  more  or  less  imbedded  in  the  large, 
sweet,  pulpy  receptacle. 

1.  F.  virginiana,  Mill.      WILD   STRAWBERRY.      Leaflets   thick, 
oval  to  obovate,  coarsely  serrate,  somewhat  hairy.     Scape  usually 
shorter  than  the  petioles,  few-flowered.    Fruit  ovoid,  akenes  imbedded 
in  deep  pits.     Common.* 

2.  F.   vesca,   L.      EUROPEAN   STRAWBERRY.     Leaflets   ovate  or 
broadly  oval,  dentate   above,  wedge-shaped   below,  slightly  hairy. 
Scape  usually  longer  than  the  petioles.      Fruit  globular  or  oval, 
akenes  adherent  to  the  nearly  even  surface  of  the  receptacle.     Com- 
mon in  cultivation.     Many  of  the  cultivated  varieties  of  strawberry 
are  hybrids  between  the  two  described  above.     The  American  form 
is  less  hairy  than  the  European  and  is  by  some  regarded  as  distinct.* 


114  FOUNDATIONS   OF  BOTANY 


X.     POTENTILLA,  L. 

Perennial  herbs,  rarely  shrubs.  Leaves  compound ;  stipules 
adnate  to  the  petiole.  Flowers  white  or  yellow,  rarely  red  ; 
solitary  or  in  cymes.  Calyx  free  from  the  ovary,  5-cleft,  with 
5  little  bracts  alternating  with  its  lobes.  Petals  5.  Stamens 
many.  Carpels  usually  many,  on  a  dry  convex  or  concave 
receptacle  ;  styles  falling  off  from  the  akenes  as  they  mature. 

1.  P.  arguta,  Pursh.      UPRIGHT  CINQUEFOIL.      An   erect,  stout 
hairy  plant,  1-4  ft.  high.     Root-leaves  long-petioled,  pinnate.     Stem- 
leaves  few,  each  of  3-7  leaflets,  the  latter  broadly  ovate  and  cut- 
toothed   or   serrate,    downy   underneath.     Flowers   large,  in   dense 
terminal  clusters  ;  the  petals  whitish  or  cream-cplor.     Rocky  hills. 

2.  P.  canadensis,  L.     COMMON  CINQUEFOIL.     Stems  slender,  pro- 
cumbent, silky-hairy,  sending  out   long  runners.     Leaflets  obovate 
wedge-shaped,  appearing  like  5  from  the  divisions  of  the  2  lateral 
ones.     Peduncles  1-flowered  in   the    axils  of   the   leaves.     Flowers 
yellow.     Common  in  dry  pastures  and  a  troublesome  weed. 

3.  P.    argentea,    L.     SILVERY  CINQUEFOIL.     Stems  prostrate   or 
ascending  and  branching,    woolly.     Leaflets  oblong,  wedge-shaped, 
those  of  the  upper  leaves  very  narrow,  with  a  few  large,  deeply  cut 
teeth,  smooth  and  green  above,  silvery  beneath,  with  a  dense  coat  of 
white  wool.     Flowers  small  and  somewhat  clustered,  yellow.     Dry 
fields  and  roadsides. 

XL     GEUM,  L. 

Erect  perennial  herbs.  Radical  leaves  crowded,  pinnate, 
with  a  very  large  terminal  leaflet.  Flowers  and  fruit  much 
as  in  Potentilla,  but  the  akenes  tailed  with  the  remains  of  the 
styles. 

1.  G.  album,  Gmelin.     WHITE    AVENS.     Stem   erect,   branching 
above,  smooth  or  finely  downy,  18-24  in.  high.     Radical  leaves  pin- 
nate, or  the   earliest  simple   and  rounded,  long-petioled,  serrate  or 
dentate,  terminal  lobe   larger  than   the    lateral  lobes;    stem-leaves 
short-petioled,  2-5-lobed  or  parted.     Flowers  on  slender  peduncles. 
Petals  white,  not  longer  than  the  sepals.     Styles  jointed  near  the 
middle,  the  lower  portion  persistent  and  hooked.     Ovaries  and  recep- 
tacle hairy,  head  of  fruit  globose.     Rich  woods.* 

2.  G.    virginianum,    L.      Stem   2-3    ft.    high,    stout   and   bristly 
hairy.     Lower  leaves  and  root-leaves  pinnate,  varying  greatly;  upper 
leaves  mostly  of  3  leaflets  or  3-parted.     Petals  white  or  pale  yellow, 


DICOTYLEDONOUS   PLANTS  115 

small,  shorter  than  the  calyx-lobes.  Pleads  of  fruit  large,  on  stout, 
hairy  peduncles  ;  the  receptacle  nearly  or  quite  smooth.  Borders  of 
woods  and  damp  thickets. 

3.  G.  rivale,  L.  WATER  AVENS,  PURPLE  AVENS,  CHOCOLATE 
ROOT.  Stem  l£-2  ft.  high,  somewhat  downy  or  hairy,  simple  or 
nearly  so.  Root-leaves  lyrate  and  somewhat  pinnate,  with  the  divi- 
sions irregular  ;  stem-leaves  few,  of  3  leaflets  or  3-lobed.  Flowers 
rather  large.  Petals  purplish-yellow,  as  long  as  the  brownish-purple 
calyx -lobes.  Styles  long,  purplish ;  stigmas  thread-like,  feathered 
with  soft  hairs,  especially  in  fruit.  Wet  meadows. 


XII.    ROSA,  Tourn. 

Erect,  running  or  climbing  prickly  shrubs.  Leaves  pinnate, 
leaflets  serrate,  stipules  adnate  to  the  petiole.  Calyx-tube 
urn-shaped,  with  a  rather  narrow  mouth.  Petals  (in  single 
roses)  5.  Stamens  many,  inserted  around  the  inside  of  the 
mouth  of  the  calyx-tube.  Ovaries  many,  hairy,  ripening 
into  bony  akenes,  enclosed  in  the  rather  fleshy  and  sometimes 
eatable  calyx-tube. 

1.  R.  blanda,  Ait.     EARLY  WILD  ROSE.     Steins  1-3  ft.  high, 
usually  without  prickles  ;  stipules  broad.     Flowers  generally  large, 
corymbed  or  solitary ;  sepals  after  flowering  closing  over  the  mouth 
of  the  calyx-tube  and  persistent.     Rocks  and  rocky  shores. 

2.  R.    Carolina,   L.      SWAMP   ROSE.     Stems   4-8  ft.   high,   with 
stout  and  generally  recurved  prickles.     Stipules  long  and  narrow ; 
leaflets  commonly  downy  beneath,  finely  serrate.    .  Flowers  several  in 
a  corymb,  bright  rose-color.     Sepals  spreading  and  falling  off  after 
flowering.     Damp  woods  and  borders  of  swamps. 

3.  R.  lucida,   Ehrh.     DWARF    WILD    ROSE.     Stems   varying   in 
height  from  less  than  a  foot  to  6  ft.,  with  stout,  somewhat  hooked 
prickles.     Stipules  rather  broad ;  leaflets  small,  thickish  and  glossy 
above,  coarsely  toothed  toward  the  tip.     Flowers  corymbed,  or  soli- 
tary, pale  rose-color.     Sepals  spreading  and  falling  off  after  flower- 
ing.    Moist  ground  and  swamps. 

4.  R.  humilis,  Marsh.     PASTURE  ROSE.     Stem  erect,   branched, 
usually  armed  with  stout   stipular  prickles  and  with  bristles,  but 
sometimes  nearly  smooth,  1-3  ft.  tall.     Leaves  mostly  of  5  leaflets ; 
stipules  entire;  leaflets   oblong-lanceolate   or   oval,  shining   above, 
pale   beneath,  sharply  serrate.     Flowers  solitary   or   2-3  together, 
2-3  in.  broad,  pink.     Peduncles  and  calyx  glandular-downy.    Calyx- 
lobes  leaf-like,  spreading,  finally  deciduous.     Styles  distinct.     Fruit 
globose,  bristly  hairy.    On  dry  soil ;  our  most  common  wild  rose.    S.* 


116  FOUNDATIONS   OF  BOTANY 

5.  R.  rubiginosa,  L.  SWEETBRIER.  Stem  erect  or  curving, 
armed  with  stout  recurved  prickles.  Leaves  with  5-7  leaflets,  the 
latter  broadly  oval,  coarsely  serrate,  glandular-bristly  beneath, 
aromatic.  Flowers  white  or  pink.  Sepals  widely  spreading, 
deciduous.  Fruit  obovate,  slightly  bristly.  Common  in  cultiva- 
tion and  sometimes  wild.* 

XIH.    PRUNUS,  Tourn. 

Trees  or  shrubs.  Leaves  simple,  with  stipules,  which  are 
often  small  or  fall  off  early.  Calyx  with  a  bell-shaped  or 
urn-shaped  tube  and  5-lobed  spreading  limb,  falling  off  after, 
flowering.  Petals  5.  Stamens  3-5  times  as  numerous,  or 
indefinite,  inserted  on  the  throat  of  the  calyx-tube.  Pistil  1, 
long-styled,  with  2  ovules,  ripening  into  a  single  stone-fruit. 

A.  Stone  oval,  compressed;  fruit  smooth  when  ripe.     Branches  often 
spiny.      (Plums.) 

1.  P.   americana,   Marsh.     WILD    PLUM.      A    small   tree,   bark 
thick  and  rough,  branches  spiny.     Leaves  ovate  or  obovate,  acumi- 
nate at  the  apex,  rounded  or  cordate  at  the  base,  sharply  serrate, 
rather  thick,  downy  beneath  ;  petioles  glandular.     Flowers  in  lat- 
eral, sessile  umbels,  appearing  with  or  before  the  leaves;  pedicels 
£-£  in.  long,  flowers  £— f  in.  in   diameter.     Calyx    downy  within; 
fruit   globose,  red  or   yellow,    ^-1    in.    in    diameter.     Common  in 
woods.* 

2.  P.  angustifolia,    Michx.     CHICKASAW    PLUM.     A   small    tree 
with  spiny  branches.     Leaves  lanceolate  or  oblong-lanceolate,  acute 
at  the  apex,  usually  obtuse  at  the  base,  finely  and  sharply  serrate, 
rather  thin,  smooth.     Flowers  in  lateral,    sessile   umbels,  pedicels 
short.     Calyx  smooth.     Fruit  yellowish-red,  subglobose,  skin  thin, 
stone  only  slightly  compressed.     In  old  fields,  S.* 

B.  Stone    deeply  furrowed   and  pitted;   fruit    downy    when    ripe. 
Branches  not  spiny.     (Peaches  and  almonds.') 

3.  P.  persica,  Sieb.  and  Zucc.     PEACH.     A  tree  with  a  rounded 
top;  bark  nearly  smooth.     Leaves  lanceolate,  taper-pointed,  finely 
serrate,   smooth   on  both   sides ;    petioles  usually   bearing  2    or  4 
crescent-shaped  or  cup-shaped  glands.     Flowers  pink,  scaly-bra cted. 
Fruit  ovoid,  with  a  seam  along  one  side.     Often  escaped  from  culti- 
vation.* 

C.  Stone  more  or  less  spherical ;  fruit  smooth  when  ripe.      Branches 
not  spiny.     (Cherries.) 


DICOTYLEDONOUS  PLANTS 


117 


4.  P.  virginiana,  L.     CHOKECHERRY.     A  shrub  or   small   tree, 
5-20  ft.  high.     Leaves  thin,  oval  or  obovate,  pale,  pointed,  sharply 
serrate.     Flowers  small,  white,  in  short  racemes.     Fruit  bright  red, 
turning  at  length  to  dark  crimson,  very  puckery  until  fully  ripe. 
River  banks  and  thickets. 

5.  P.  serotina,  Ehrh.     WILD  BLACK  CHERRY.     Often  becoming  a 
large  tree;  bark  on  old  trees  rough,  nearly  black.     Leaves  rather 
thick,  oval  to  lanceolate-ovate,  acute  or  taper-pointed  at  the  apex, 
finely  serrate  with  calloused  teeth,  smooth  above,  downy  on  the  veins 
beneath.     Racemes  terminal,  long  and   spreading.     Flowers  white. 
Fruit   globose,   about  \  in.    in    diameter,    purplish-black.     In   rich 
woods.     Wood  much  used  in  cabinet-making.* 

6.  P.    Cerasus,    L.       CHERRY.      Often    becoming    a    large    tree. 
Leaves  oval  or  ovate,  acute  or  taper-pointed  at  the  apex,  rounded  at 
the  base,  irregularly  serrate-dentate,  smooth  on  both  sides,  resinous 
when  young.     Flowers  in  lateral  umbels,  white ;  pedicels  long  and 
slender.     Fruit  globose,  red  or  black.     This  is  the  European  species 
from  which  most  of  our  cultivated  varieties  have  been  developed.* 

46.   LEGUMINOS^.     PULSE  FAMILY. 

Herbs,  shrubs,  or  trees.  Leaves  alternate,  usually  com- 
pound (either  pinnately  or  palmately),  with  stipules,  the  leaf- 
lets mostly  entire.  Calyx  of  5  sepals,  which  are  more  or  less 
united,  often  somewhat  irregular.  Corolla,  of  5  petals,  often 


FIG.  14.  — I,  Diagram  of  Flower  of  Sweet  Pea,  Lathyrus  odoratus.    II,  Vertical 
Section  of  Flower  (magnified).    Ill,  Calyx  (magnified). 


Ill 


FIG.  15.  — I,  Stamens  and  Pistil  of  Sweet  Pea  (magnified).    II,  Fruit..  Ill,  Part  of 
Fruit,  showing  one  seed. 


118  FOUNDATIONS   OF   BOTANY 

papilionaceous  or  somewhat  regular,  in  No.  XV  much  reduced. 
Stamens  diadelphous  (Fig.  15),  monadelphous,  or  distinct. 
Ovary  simple,  free  from  the  calyx.  Fruit  usually  a  1-celled 
pod  (Fig.  15).  Seeds  one  or  several,  without  endosperm. 

A. 

Flower  regular,  small.     Stamens  hypogynous.     Leaves  twice  pinnate. 

Petals  not  united  to  each  other.  Stamens  5  or  10.  Pod 
smooth.  Desmanthus,  I. 

Corolla  gamopetalous,  5-cleft.  Stamens  8  or  10.  Pod  minutely 
prickly  or  rough.  Schrankia,  II. 

B. 

Trees.  Flowers  somewhat  or  not  at  all  papilionaceous ;  sometimes  almost 
regular.  The  upper  petal  inside  the  others  in  the  bud.  Stamens  10 
or  less,  usually  not  united  to  each  other,  borne  on  the  calyx. 

Flowers  imperfectly  papilionaceous.     Leaves  simple. 

Cercis,  III. 

Flowers  not  papilionaceous.     Thornless.  Gymnocladus,  IV. 

Flowers  not  papilionaceous.     Thorny.  Gleditschia,  V. 

C. 

Herbs  or  trees.  Flowers  decidedly  papilionaceous.  The  upper  petal 
external  in  bud  and  enclosing  the  others.  Stamens  10,  not  united  to 
each  other. 

Trees.  Cladrastis,  VI. 

Herbs.  Baptisia,  VII. 

D. 

Shrubs  with  a  corolla  of  one  petal  only.  Amorpha,  XV. 

E. 

Herbs,  shrubs,  or  trees.  Flowers  decidedly  papilionaceous.  Stamens 
monadelphous  or  diadelphous  (in  the  latter  case  usually  9  and  1,  a*  in 
Fig.  15). 


DICOTYLEDONOUS  PLANTS  119 

1.  Stamens  with  anthers  of  two  forms.     Leaves  palmately  com- 

*  pound. 

Herbs.     Leaves  with  many  leaflets.  Lupinus,  VIII. 

Trees.  Laburnum,  IX. 

Low  shrubs.  Cytisus,  X. 

2.  Anthers  all  alike  except  in  No.  14. 

Leaves  usually  with  3  leaflets.     Leaflets  with   fine  teeth, 

except  in  No.  14. 

(a)  Pod  coiled.  Medicago,  XI. 

(&)  Pod  not  coiled.     Flowers  in  racemes.  Melilotus,  XII. 

(c)  Pod  not  coiled.     Flowers  in  heads.  Trifolium,  XIII. 

(d)  Leaflets  entire.  Psoralea,  XIY. 

3.  Leaves  odd-pinnate,  with  more  than  3  leaflets. 

(e)  Low  woody  shrubs.  Amorpha,  XV. 
(/)  Tall  twining  shrubs.                                  Wistaria,  XVI. 
(g)  Trees.                                                           Robinia,  XVII. 
(A)  Herbs.                                                    Astragalus,  XVIII. 

4.  Leaves  pinnate,  the  midrib  prolonged  into  a  tendril. 

(i)  Leaflets  usually  many  pairs.  Style  slender,  bearded 
only  at  the  tip  or  all  round  the  upper  portion.  Pod 
2-several-seeded.  Vicia,  XIX. 

(/)  Leaflets  few  or  several  pairs.  Style  bearded  along  one 
face  only.  Pod  several-seeded.  Lathyrus,  XX. 

(&)  Leaflets  1-3  pairs.  Style  enlarged  above,  grooved  on 
the  back.  Pod  several-seeded  ;  seeds  large,  globular 
or  nearly  so.  Pisum,  XXI. 

I.    DESMANTHUS,  Willd. 

Shrubs  or  perennial  herbs ;  stems  erect  or  diffuse,  smooth. 
Leaves  abruptly  twice-pinnate  ;  stipules  small.  Flowers  in 
heads  or  spikes,  on  axillary  peduncles,  the  upper  perfect,  the 
lower  often  staminate  or  neutral.  Calyx  5-toothed.  Corolla 
of  5  distinct  petals  or  5-cleft.  Stamens  5-10,  distinct. 
Ovary  nearly  sessile,  flat,  several-seeded.* 


120  FOUNDATIONS   OF   BOTANY 

1.  D.  brachylobus,  Benth.  DESMANTHUS.  Stem  erect  or  ascend- 
ing, smooth,  1-4  ft.  high.  Pinnae  6-14  pairs,  each  with,  a  minute 
gland  at  the  base ;  leaflets  20-30  pairs,  small,  linear.  Heads  glo- 
bose. Stamens  5.  Pods  several,  on  a  peduncle  2-3  in.  long,  curved, 
flat,  2-valved,  3-6-seeded.  Open,  sandy  fields.* 

H.    SCHRANKIA,  Willd. 

Perennial  herbs  ;  stems  reclining  or  prostrate,  prickly,  2-5 
ft.  long.  Leaves  twice-pinnate  ;  stipules  bristly.  Flowers 
perfect  or  somewhat  monoecious,  in  axillary  peduncled  heads. 
Calyx  minute.  Corolla  tubular,  5-cleft.  Stamens  8-10,  dis- 
tinct. Pod  long,  prickly,  1 -celled.* 

1.  S.  uncinata,  Willd.  SENSITIVE  BRIER,  SENSITIVE  ROSE, 
SHAME  VINE.  Plant  covered  with  hooked  prickles.  Leaflets  ellip- 
tical, with  a  conspicuous  network  of  veins  beneath ;  leaves  closing 
gradually  after  being  touched.  Flowers  rose-colored.  Pods  nearly 
cylindrical,  2  in.  long.  Dry,  sandy  soil  and  rolling  prairies,  espe- 
cially S.  and  W. 

IH.    CERCIS,  L. 

Trees.  Leaves  simple  with  stipules.  Flowers  in  axillary 
clusters,  papilionaceous.  Calyx  bell-shaped,  5-toothed.  Sta- 
mens 10,  distinct.  Ovary  short-stalked ;  ovules  several. 
Fruit  a  flattened  pod. 

1.  C.  canadensis,  L.  REDBUD.  A  small  tree,  10-20  ft.  high,  wood 
hard  but  weak,  bark  smooth,  dark-colored.  Leaves  broadly  cordate, 
abruptly  acute,  rather  thick,  very  smooth  above,  often  slightly 
downy  below.  Flowers  several  in  a  cluster,  appearing  before  the 
leaves,  pinkish-purple.  Pod  oblong,  compressed,  many-seeded.  Com- 
mon on  rich  soil,  especially  S.* 


IV.     GYMNOCLADUS,  Lam. 

A  large,  thornless  tree,  its  twigs  few  and  stout.  Leaves 
very  large,  twice  pinnately  compound,  without  stipules. 
Flowers  regular,  whitish,  dioecious  or  somewhat  monoecious, 
in  racemes  at  the  ends  of  the  branches.  Calyx-tube  rather 
long,  its  5  lobes  spreading.  Petals  oblong,  all  alike,  inserted 
with  the  stamens  on  the  throat  of  the  calyx.  Stamens  of 
the  fertile  flowers  usually  not  pollen-bearing.  Pod  hard,  flat, 


DICOTYLEDONOUS  PLANTS  121 

partly  filled  with  a  sweet  substance,  slow  in  opening.     Seeds 
several,  flattish,  over  ^  in.  in  diameter,  very  hard  and  shining. 

1.  G.  canadensis,  Lam.  KENTUCKY  COFFEE  TREE.  Tree  50  ft. 
or  more  in  height,  with  rough  gray  bark.  Leaves  2-3  ft.  long,  the 
leaflets  vertical.  Pods  sometimes  nearly  1  ft.  long.  Rich  soil  and 
river  bottoms,  especially  S.  and  W. 

V.     GLEDITSCHIA,  L. 

Large  trees ;  bark  dark-colored,  nearly  smooth.  Leaves 
usually  pinnately  twice  compound  ;  leaflets  serrate.  Flowers 
somewhat  monoecious,  in  small  spike-like  racemes.  Calyx 
spreading,  3-5-cleft.  Petals  as  many  as  the  sepals  and 
inserted  at  the  summit  of  the  tube.  Stamens  5-10,  distinct, 
inserted  with  the  petals.  Ovary  nearly  sessile,  ovoid  or 
elongated.  Fruit  a  1  or  many  seeded,  leathery  pod.* 

1.  G.  Triacanthos,  L.  HONEY  LOCUST.  A  large  tree,  usually  armed 
with  stout,  branched  thorns,  which  are  sometimes  a  foot  or  more  in 
length.  Leaves  petioled  ;  leaflets  short-stalked,  lanceolate-oblong, 
base  inequilateral,  smooth  above,  often  downy  below.  Racemes  soli- 
tary or  in  small  clusters,  drooping.  Flowers  inconspicuous,  greenish. 
Pod  linear-oblong,  often  12-15  in.  long  by  1  in.  wide,  twisted,  many- 
seeded,  smooth  and  shiny,  pulpy  within.  In.  rich  woods.  [The 
thorns  are  plainly  modified  branches  bearing  dormant  buds,  and 
often  partially  developed  leaves.  The  early  spring  leaves  are  usually 
only  once  compound,  while  those  of  later  growth  are  almost  invaria- 
bly twice  compound.  Often  a  single  leaf  will  show  both  forms  of 
compounding.]* 

VI.    CLADRASTIS,  Raf. 

A  moderate-sized  tree  with  smooth  dark  gray  bark  and 
yellow  wood.  Leaves  of  7-11  smooth  oval  or  ovate  leaflets. 
Flowers  creamy-white,  in  long,  drooping  panicles.  Calyx 
5-toothed.  Standard  large,  nearly  round,  reflexed  ;  petals  of 
the  keel  and  wings  separate  and  straight.  Stamens  10, 
unconnected  with  each  other.  Pod  borne  on  a  short  stalk 
above  the  calyx.  Seeds  4-6. 

1.  C.  tinctoria,  Raf.  YELLOW  WOOD.  Tree  50  ft.  or  less  in 
height,  much  branched,  with  a  round,  spreading  top.  Hillsides,  in 
fertile  soil,  south  central  states.  Also  considerably  planted  as  a 
shade  tree. 


122  FOUNDATIONS   OF   BOTANY 


VII.    BAPTISIA,  Vent. 

Perennial  herbs;  stems  erect,  widely  branched.  Leaves 
simple  or  palmate,  of  3  leaflets.  Flowers  in  racemes.  Calyx 
4-5-lobed,  persistent,  the  upper  lobe  usually  longer  and 
notched  ;  standard  rounded,  its  sides  reflexed,  wings  about 
as  long  as  the  keel.  Stamens  10,  distinct.  Pod  stalked, 
long-pointed  by  the  remains  of  the  style.  Plants  usually 
becoming  black  in  drying.* 

1.  B.  tinctoria,  R.  Br.      WILD  INDIGO.      Stem  smooth,  slender, 
2-4   ft.    high;  branches   slender.      Leaves  of    3  leaflets,   on   short 
petioles,  the  upper  nearly  sessile  ;  stipules  minute,  quickly  deciduous. 
Leaflets  obovate  to  oblauceolate,  obtuse  at  the  apex,  wedge-shaped 
at  the  base,  entire.     Racemes  numerous,  terminal.     Flowers  yellow, 
£  in.  long.     Pod  globose,  ovoid,  on  a  stalk  about  the  length  of  the 
calyx,  point  long  and  slender.     Plant  blackening  in  drying.     Com- 
mon on  dry,  sandy  soil.* 

2.  B.  leucophaea,    Nutt.      Low,    hairy,    and   branching.      Leaves 
nearly  sessile,  leaflets  oblanceolate  or  obovate-spatulate.    Stipules  tri- 
angular-ovate, large,  persistent ;  bracts  large  and  leaf-like.    Racemes 
long.    Flowers  large,  yellowish-white.    Pod  ovoid,  swollen.    Prairies 
and  open  woods,  W.  and  S.  . 

3.  B.  leucantha,  Torr.  and  Gr.     Stout,  smooth,  and  covered  with 
a  bloom,  3  ft.  or  more    high,  with  spreading  branches.     Petioles 
short  ;    lanceolate  stipules  and   bracts  falling  off   early.     Racemes 
erect.     Flowers  large,  white.     Pods  ellipsoidal,  2  in.  long,  borne  on 
a  stalk  twice  as  long  as  the  calyx.     Rich  river  bottoms  and  prairies. 

4.  B.  alba,    R.    Br.     WHITE  WILD  INDIGO.     Stem  smooth  and 
with  a  bloom,  often  purple,  2-3  ft.  high  ;  branches  slender,  spreading. 
Leaves  petioled,  with  3  leaflets;   stipules  minute,  soon  deciduous. 
Flowers  white,  mostly  in  a  single  raceme  which  is  1-3  ft.  long,  with 
occasionally  lateral,  few-flowered   racemes.     Pod  linear-oblong,  the 
point  very  slender  and  soon  deciduous.    Plant  unchanged  in  drying. 
In  damp  soil.* 

5.  B.  australis,    R.    Br.     BLUE    FALSE    INDIGO.     Stem    smooth, 
stout,  2-4  ft.  high.      Leaves  of   3    leaflets,  short-petioled ;  stipules 
lanceolate,    persistent,    longer   than  the   petioles  ;    leaflets    oblong, 
wedge-shaped   or   narrowly  obovate,  entire.      Flowers  bright  blue, 
1  in.  long,  in  terminal,  erect,  loosely  flowered  racemes ;  stalk  about 
the  length  of   the  calyx.      Pod   oblong,  with  a  slender,  persistent 
point.     Banks  of  rivers ;  often  cultivated  for  ornament.* 


DICOTYLEDONOUS   PLANTS  123 


Vin.    LUPINUS,  Tourn. 

Biennial  or  perennial  herbs.  Leaves  simple  or  palmately 
compound.  Flowers  showy,  in  terminal  racemes.  Calyx 
2-lipped,  5-toothed.  Standard  round,  with  the  sides  reflexed, 
keel  scythe-shaped.  Stamens  monadelphous,  anthers  alter- 
nately oblong  and  roundish.  Ovary  sessile  ;  matured  pod 
oblong,  several-seeded,  often  compressed  between  the  seeds.1* 

1.  L.  perennis,  L.  Perennial ;  stem  erect,  downy,  12-18  in.  high. 
Leaves  palmately  7-9  foliate ;  leaflets  obovate  or  oblanceolate,  obtuse 
and  mucronate  at  the  apex,  slightly  downy  ;  petiole  slender  ;  stipules 
small.  Racemes  terminal,  slender,  loosely  many-flowered.  Flowers 
purple,  blue,  pink,  or  white.  Pod  oblong,  densely  downy,  few-seeded. 
Dry,  sandy  soil.* 

IX.    LABURNUM,  Benth. 

Trees  or  shrubs.  Leaves  of  3  leaflets,  with  very  small 
stipules  or  none.  Flowers  golden-yellow,  in  slender,  drooping 
racemes.  Calyx  2-lipped,  the  upper  lip  2-toothed,  the  lower 
3-toothed.  Standard  ovate,  upright,  of  the  same  length  as 
the  straight  wings.  Stamens  diadelphous  (9  and  1).  Ovary 
and  pod  somewhat  stalked  above  the  calyx,  several-seeded. 

1.  L.  vulgare,  Gris.  LABURNUM,  GOLDEN  CHAIN.  A  small  tree, 
with  smooth,  greenish  bark.  Leaves  with  slender  petioles  ;  leaflets 
oblong-ovate,  acute  at  the  base,  taper-pointed,  downy  beneath. 
Flowers  showy,  in  graceful  racemes.  Cultivated  from  Europe. 


X.    CYTISUS,  L. 

Shrubs,  rarely  spiny.  Leaves  of  1-3  leaflets  or  none  ;  stip- 
ules very  small.  Calyx  2-lipped,  the  upper  lip  slightly 
2-toothed,  the  lower  3-toothed.  Keel  straight  or  a  little 
curved,  blunt,  turned  down  after  flowering.  Stamens  with 
their  filaments  all  united  ;  anthers  every  other  one  short  and 
attached  by  its  center,  the  alternate  ones  long  and  fastened 
by  their  bases.  Style  curved  in,  or,  after  the  flower  opens, 
coiled  up.  Pod  flat,  long,  many-seeded. 

1.  C.  canariensis,  Steud.  A  shrub  with  many  rather  stiff,  erect, 
slender  branches.  Leaves  abundant,  very  small,  covered  with  soft 


124  FOUNDATIONS   OF  BOTANY 

gray  hairs  ;  leaflets  3,  obovate.  Flowers  rather  small,  yellow,  in 
somewhat  erect  racemes.  Cultivated  in  greenhouses.  From  the 
Canary  Islands. 

XI.    MEDICAGO,  Tourn. 

Annual  or  perennial  herbs  ;  leaves  petioled,  of  3  toothed 
leaflets.  Flowers  in  terminal  and  axillary  spikes  or  racemes. 
Calyx  5-toothed,  the  teeth,  short  and  slender.  Standard 
oblong,  much  longer  than  the  wings  or  keel.  Stamens  10, 
diadelphous.  Ovary  sessile.  Pod  1-several-seeded,  coiled, 
not  splitting  open,  often  spiny.* 

1.  M.  sativa,  L.     ALFALFA.     Perennial;  stems  erect,  branching, 
downy  when   young,   becoming   smooth   with   age,    2-3   ft.    high. 
Leaves  short-petioled ;  leaflets  obovate,  sharply  dentate  towards  the 
apex,  obtuse  or  sometimes  notched  or  mucronate  ;  stipules  lanceolate, 
entire.     Flowers  blue,  small,  in  rather  close  spikes  ;  pods  downy, 
coiled,  few-seeded.     Introduced  from  Europe,  and  cultivated  for  hay 
and  pasture.* 

2.  M.  lupulina,  L.     BLACK  MEDICK,  NONESUCH.     An  annual  or 
biennial,  much  branched,  reclining  herb,  with  stems  from  6-20  in. 
long.      Leaves  very  short-petioled;  leaflets  obovate,  acute,  ^-f  in. 
long,  toothed  near  the  tip.     Flowers  small,  yellow,  in  short  spikes. 
Pods  very   small,   1-seeded,  kidney-shaped,  black.     Roadsides  and 
waste  ground,  introduced  from  Europe. 

XH.    MELILOTUS,  Tourn. 

Annual  or  biennial  herbs.  Leaves  petioled,  of  3  leaflets. 
Flowers  small,  white  or  yellow,  in  c  se  axillary  and  terminal 
racemes.  Calyx  5-toothed,  the  teetn  nearly  equal.  Standard 
erect,  wings  and  keel  cohering.  Stamens  10,  diadelphous. 
Pod  longer  than  the  calyx,  1-4-seeded.* 

1.  M.  alba,  Lam.     MELILOTUS.    Biennial;  stem  erect,  branching, 
smooth  or  the  young  branches  slightly  downy.     Leaflets  oblong  or 
oblanceolate,  rounded  or  truncate  at  the  apex,  serrate ;  stipules  small. 
Racemes  long,  slender,  erect.    Flowers  white.    Standard  longer  than 
the  wings  and  keel.     Pod  ovoid,  wrinkled,  drooping,  mostly  1-seeded, 
scarcely  opening.     Common  as  a  weed  and  widely  cultivated.* 

2.  M.  officinalis,  Willd.      YELLOW   SWEET    CLOVER.      A  stout, 
upright,  branching  herb,  2-4  ft.  high,  looking  much  like  the  preced- 
ing species,  but  coarser.     Flowers  yellow.     Waste  ground  and  road- 
sides.    Introduced  from  Europe. 


DICOTYLEDONOUS   PLANTS  125 

XIII.    TRIFOLIUM,  Tourn. 

Annual,  biennial,  or  perennial  herbs.  Stems  more  or  less 
spreading.  Leaves  petioled,  of  3  toothed  or  serrate  leaflets  ; 
stipules  adnate  to  the  petioles.  Flowers  white,  yellow,  or 
red,  in  heads.  Calyx  5-cleft,  the  teeth  nearly  equal  and 
subulate.  Petals  withering-persistent,  keel  shorter  than  the 
wings.  Stamens  diadelphous.  Pod  smooth,  1-6-seeded, 
scarcely  opening.* 

1.  T.  procumbens,  L.    Low  HOP-CLOVER.    Annual ;  stem  slender, 
erect,  or  spreading,  downy,  6-10  in.  long.      Leaves  short-petioled ; 
leaflets  obovate  or  obcordate,  finely  dentate,  the  middle  one  distinctly 
stalked  ;  stipules  lanceovate.    Flowers  yellow,  reflexed  in  fruit.    Pod 
1-seeded.     Common  on  clay  soil,  in  waste  places.* 

2.  T.  incarnatum,  L.     CRIMSON  CLOVER.     Annual  ;   stem  erect, 
somewhat  branched,  downy,  1-2  ft.  high.     Lower  leaves  long-,  the 
upper  short-petioled;  leaflets  obovate  or  wedge-shaped,  toothed  at 
the  apex.     Flowers  bright  crimson,  sessile,  in  terminal  heads  which 
finally  become  much  elongated.     Calyx  silky,  its  lobes  long  and 
plumose.     Introduced  and  cultivated  for  fodder. 

3.  T.  pratense,  L.     RED  CLOVER.     Biennial  or  short-lived  peren- 
nial ;  stems  spreading,  branching,  downy,  1-3  ft.  long.    Leaves  long- 
petioled  ;  stipules  large  ;  leaflets  oval  to  obovate,  finely  toothed,  often 
with  a  dark  triangular  spot  near  the  center.     Flowers  red  or  purple, 
in  globose  heads,  erect  in  fruit.     Calyx-teeth  bristle-shaped,  hairy. 
Pod  1-3  seeded.     Introduced  and  widely  cultivated.* 

4.  T.    carolinianum,    Michx.      CAROLINA    CLOVER.      Perennial; 
stems  spreading  or  ascending,  much-branched,  downy,  6-10  in.  long. 
Leaves  short-petioled  ;  leaflets  small,  obovate  or  obcordate,  slightly 
toothed.     Heads  small,  globose,  on  long  peduncles.     Flowers  white, 
tinged  with  purple,  reflexed  in  fruit.     Pod  4-seeded.     Common  in 
waste  places  S.* 

5.  T.  repens,  L.      WHITE    CLOVER.      Perennial;    stems  widely 
branching  at  the  base,  prostrate  and  creeping,  nearly  smooth,  6-12 
in.  long.     Leaves  long-petioled ;  leaflets  oval,  obovate  or  obcordate, 
minutely  toothed.     Heads  globose,  long-peduncled.     Flowers  white, 
reflexed  in  fruit.      Pod  3-4-seeded.      Introduced;    common  about 
houses  and  in  pastures.* 

6.  T.  hybridum,  L.     ALSIKE  CLOVER.      Perennial,  considerably 
resembling  No.  5,  but  the  stems  more  upright  and  stouter.     Leaflets 
varying    from    broadly    ovate    to    ovate-lanceolate,  mucronate    or 
slightly  notched,  the  margins  fringed  with  hairs ;  stipules  prolonged 
into  bristle-like  points.     Flowers  rose-color  and  white,  very  fragrant. 
In  fields  and  along  roadsides.     Introduced  from  Europe. 


126  FOUNDATIONS   OF   BOTANY 


XIV.     PSORALEA,  L. 

Perennial  herbs  ;  whole  plant  glandular-dotted.  Leaves  of 
3-5  leaflets  ;  stipules  cohering  with  the  petioles.  Flowers  in 
axillary  or  terminal  spikes  or  racemes.  Calyx  5-cleft,  the 
lobes  nearly  equal.  Standard  ovate  or  orbicular,  keel 
incurved,  obtuse.  Stamens  monadelphous  or  diadelphous, 
5  of  the  anthers  often  undeveloped.  Ovary  nearly  sessile. 
Pod  included  in  the  calyx,  often  wrinkled,  remaining  closed, 
1-seeded.* 

1.  P.  melilotoides,  Michx.     SAMSON'S  SNAKEROOT.     Stem  erect, 
slender,  branching  above,  downy,  1-2  ft.  high.     Leaves  of  3  leaflets ; 
petioles    shorter   than   the    leaflets ;    stipules    awl-shaped ;    leaflets 
elliptical  or  oblong-lanceolate,  sparingly  glandular-dotted,  the  termi- 
nal one  stalked.     Loosely  flowered  spikes  axillary  and  terminal,  on 
peduncles  much  longer  than  the  leaves.      Flowers  blue  or  purple, 
about  £  in.  long.      Pod  compressed-globose,  wrinkled  transversely. 
Dry  soil.* 

2.  P.  tenuiflora,  Pursh.     Upright,  slender,  bushy  and  branching, 
2-4  ft.  high,  covered  wheu  young  with  a  fine  grayish  down.    Leaves 
palmately  compound,  with  3-5  linear  to  obovate-oblong  leaflets,  cov- 
ered with  glandular  dots.     Flowers  i-£  in.  long,  loosely  racemed. 
Pod  rough  with  glands.      Prairies,  W. 

3.  P.  esculenta,  Pursh.     POMME  BLANCHE,  TIPSIN,  DAKOTA  TUR- 
NIP.    Clothed  with  roughish  hairs.     Stem  5-15  in.  high,  erect  and 
stout.      Root   turnip-shaped,    starchy,    eatable.      Leaves   palmately 
compound,  with  5  lance-oblong   leaflets.     Flowers  £  in.  long,  in  a 
dense   ellipsoidal   spike.     Pod   hairy,    with   a   pointed   tip.      High 
prairies  or  plains,  especially  N.  W. 


XV.    AMORPHA,  L. 

Small  shrubs,  glandular-dotted.  Leaves  odd-pinnate.  Flowers 
purple,  blue,  or  white,  in  slender  spikes  or  racemes.  Calyx 
5-toothed,  persistent.  Standard  obovate,  concave,  wings  and 
keel  none.  Stamens  monadelphous,  projecting  much.  Ovary 
sessile.  Pod  curved,  glandular-roughened,  1-2-seeded,  never 
opening.* 

1.  A.  fruticosa,  L.  FALSE  INDIGO.  A  shrub  6-15  ft.  high,  with 
smooth,  dark-brown  bark.  Leaves  petioled ;  leaflets  15-21,  short- 
stalked,  oblong,  obtuse  or  notched,  sparingly  punctate  with  clear 
dots.  Slender  flowering  spikes,  panicled  or  solitary,  4-6  in.  long. 


DICOTYLEDONOUS  PLANTS  127 

Flowers  blue  or   purple.     Calyx-teeth  short,  nearly   equal,    downy. 
Pod  glandular.     River  banks.* 

XVI.    WISTARIA,  Nutt. 

Tall,  twining  shrubs.  Leaves  odd-pinnate.  Racemes  ter- 
minal. Flowers  large  and  showy.  Calyx  2-lipped,  the  upper 
lip  2-cleft,  short,  the  lower  longer  and  3-cleft.  Standard 
large,  round,  with  2  calloused  ridges  at  the  base,  wings 
eared  at  the  base,  keel  scythe-shaped.  Pod  long,  stalked, 
leathery,  2-valved,  several-seeded.* 

1.  W.    frutescens,    Poir.     WISTARIA.     Stem  climbing   30-40  ft., 
often  2-3  in.  in  diameter  at  the  base ;  branches  and  leaves  downy 
when  young,  becoming  smoother  with  age.     Leaves  short-petioled ; 
stipules  minute ;  leaflets  9—17,  ovate-lanceolate,  acute  at  the  apex, 
rounded   at   the   base.     Racemes    large,    densely  flowered.      Calyx 
downy.     Corolla  lilac-purple,  one  wing  with  a  short  and  one  with  a 
long  appendage  at  the  base.     Pod  2-3  in.  long,  2-4-seeded.     River 
banks  S.     Often  cultivated  for  ornament.* 

2.  W.  chinensis,  DC.     CHINESE   WISTARIA.     Larger  and  faster 
growing  than  No.  1.      Racemes  longer  and   more  slender.     Wing- 
appendages  equal.     Seldom  fruiting  in  this  region.     Cultivated  from 
China  or  Japan. 

XVII.    ROBINIA,  L. 

Trees  or  shrubs.  Leaves  odd-pinnate  ;  stipules  often  spiny. 
Flowers  showy,  in  axillary  racemes.  Calyx  short,  5-toothed, 
the  two  upper  teeth  shorter  and  partially  united.  Standard 
large,  orbicular,  reflexed,  keel  obtuse.  Stamens  diadelphous. 
Style  bearded  on  one  side.  Pod  compressed,  several-seeded.* 

1.  R.  Pseudacacia,  L.  BLACK  LOCUST.  A  tree  of  medium  size; 
bark  rough  and  nearly  black;  twigs  and  leaves  smooth.  Leaflets 
9-15,  ovate  or  oblong,  obtuse  and  slightly  mucronate  at  the  apex; 
stipules  forming  persistent  spines.  Racemes  loose,  pendulous,  3-5  in. 
long.  Flowers  white,  fragrant.  Pod  smooth,  4-8-seeded.  Intro- 
duced and  quite  common ;  w^ood  very  durable  when  exposed  to  the 
weather,  and  extensively  used  for  posts.* 

XVIII.    ASTRAGALUS,  Tourn. 

Mostly  perennial  herbs.  Leaves  odd-pinnate.  Flowers  in 
spikes  or  racemes.  Calyx  5-toothed.  Petals  long,  erect,  with 


128  FOUNDATIONS   OF   BOTANY 

claws.  Standard  narrow.  Stamens  diadelphous  (9  and  1). 
Pod  usually  swollen,  sometimes  fleshy  and  eatable,  several- 
many-seeded. 

1.  A.  caryocarpus,  Ker.  GROUND  PLUM,  BUFFALO  APPLE.  Covered 
with  pale,  close-lying  down.    Leaflets  narrow,  oblong.    Flowers  violet- 
purple,  in  a  short,  narrow  raceme.    Fruit  looking  like  a  small,  green, 
pointed  plum,  about  f  in.  in  diameter,  eatable.     N".  W.,  and  S.  to 
Texas. 

2.  A.    mexicanus,  A.  DC.      PRAIRIE    APPLE.      Smooth    or   with 
some  loose  hairs.     Corolla  cream-color,  with  the  tip  bluish.     Fruit 
globular,  not  pointed,  eatable.     Prairies,  Illinois  and  S.  W. 

3.  A.  canadensis,  L.     Erect,  often  tall  (1-4  ft.  high),  more  or  less 
downy.     Leaflets  oblong,    21-27.     Flowers  pale    greenish,    in   long 
spikes.    Pod  dry,  2-celled,  sessile.    River  bottoms,  prairies,  and  woods. 


XIX.    VICIA,  Tourn. 

Climbing  or  spreading  herbs.  Leaves  odd-pinnate,  usually 
ending  in  a  tendril.  Leaflets  many,  entire  or  toothed  at  the 
tip  ;  stipules  half  arrow-shaped.  Flowers  blue,  purple,  or  yel- 
low, in  axillary  racemes.  Calyx-teeth  nearly  equal.  Wings 
adnate  to  the  keel.  Stamens  diadelphous  (9  and  1)  ;  fila- 
ments thread-shaped,  anthers  all  alike.  Style  bent,  smooth  or 
downy  all  round  or  bearded  below  the  stigma  ;  ovules  usually 
many.  Pod  flattened,  2-several-seeded.  Seeds  globular. 

1.  V.  americana,  Muhl.     WILD  VETCH,  BUFFALO   PEA.     Peren- 
nial.     Smooth,  1-3  ft.  high.      Leaflets    10-14,  elliptical  or  ovate- 
oblong,  obtuse.      Peduncles  shorter  than  the  leaves,  4-8-flowered. 
Flowers  bluish-purple,  f  in.  long.     Common  N.  and  W. 

2.  V.  caroliniana,  Walt.     Perennial.     Smooth  or  nearly  so,  4-6  ft. 
high.     Leaflets    8-24,  narrowly   oblong,    blunt.     Peduncles   loosely 
flowered.    Flowers  smaller  than  in  No.  1,  whitish  or  tipped  with  pale 
purple.     River  banks. 

3.  V.    sativa,    L.      COMMON   VETCH.      Annual.      Stem    simple, 
smooth  or   downy,  reclining,  1-3  ft.  long.     Leaves  short-petioled ; 
leaflets    5-7    pairs,  obovate-oblong   to  linear,  obtuse,  notched  and 
mucronate  at  the  apex.     Flowers  in  pairs,  nearly  sessile  in  the  axils, 
pale  purple,  £-1  in.  long.     Pod  linear,  several-seedecf.     Introduced 
from  Europe  and  common  in  cultivation.* 


DICOTYLEDONOUS   PLANTS  129 


XX.     LATHYRUS,  Tourn. 

Like  Vicia  excepting  that  the  leaflets  are  fewer  and  the 
style  is  bearded  on  the  side  toward  the  standard. 

1.  L.    venosus,  Muhl.     VEINY  VETCH.     Perennial.     Stem  stout, 
prominently  angled,  climbing   or   reclining,  2-5   ft.  long.     Leaves 
short-petioled ;  stipules  large,  lanceolate ;  leaflets  5-7  pairs,  broadly 
ovate-obtuse,  mucronate.     Peduncles  nearly  as   long  as  the  leaves, 
many-flowered.      Flowers    purple,   ^  in.   long.      Calyx-teeth    very 
unequal.     Pod  linear,  veined,  4-6-seeded.     Shady  banks  and  moist 
prairies.* 

2.  L.  maritimus,  Bigelow.     BEACH  PEA.    Perennial.     Stem  stout, 
1-2  ft.  high.     Stipules  broadly  ovate  and  heart  or  halberd  shaped, 
nearly  as  large  as  the  6-12  leaflets,  of  which  the  lower  pair  is  the 
largest ;    tendrils  pretty  large.     Flowers  large,  blue  or  purple.     Sea- 
shores and  beaches  of  the  Great  Lakes. 

3.  L.  palustris,  L.     WILD  PEA.     Stem  frequently  winged,  slender, 
and  climbing  by  delicate  tendrils  at  the  ends  of  the  leaves.    Stipules 
narrow  and  pointed  ;  leaflets  4-8,  narrowly  oblong  to  linear,  acute. 
Peduncles   bearing  2-6   pretty  large,   drooping,  blue,    purple,   and 
white  flowers.     Damp  thickets  and  borders  of  swamps. 

4.  L.    odoratus,    L.      SWEET    PEA.      Annual.      Stem   roughish- 
hairy,  it  and  the  petioles  winged.     Leaflets  only  one  pair,  oval  or  ob- 
long.    Flowers  large,  2  or  3  on  the  long  peduncles,  sweet-scented, 
white,  rose-color,  purple,  or  variegated.     Cultivated  from  Europe. 

XXI.    PISUM,  L. 

Climbing  or  prostrate  herbs.  Style  enlarged  above,  grooved 
on  the  back,  soft-hairy  down  on  the  inner  edge.  Leaflets 
1-3  pairs.  Mowers  and  fruit  much  like  those  of  Lathyrus. 

1.  P.  sativum,  L.  COMMON  PEA.  Annual.  Smooth  and  covered 
with  a  bloom.  Leaflets  usually  2  pairs ;  tendrils  branching ;  stip- 
ules large,  ovate,  rather  heart-shaped  at  the  base.  Peduncle  several- 
flowered.  Flowers  white,  bluish,  reddish,  or  variegated.  Pods  large  ; 
seeds  globular  or  somewhat  flattened  and  wrinkled.  There  are 
many  varieties,  differing  greatly  in  size,  of  the  plant  and  of  the 
fruit.  Cultivated  from  Europe  (?). 

47.   GERANIACE^.     GERANIUM  FAMILY. 

Herbs  or  small  shrubs.  Leaves  simple,  usually  with  glan- 
dular hairs  which  secrete  an  aromatic  oil.  Flowers  perfect, 


130  FOUNDATIONS   OF  BOTANY 

axillary  and  solitary  or  clustered,  regular  or  slightly  irregular 
hypogynous,  tj^eir  parts  in  fives.  Stamens  5  or  10,  monadel- 
phous  at  the  ba^e.  Carpels  5,  each  2-ovuled,  splitting  away 
with  their  long  stj^es  when  ripe  from  a  central  axis  and  thus 
scattering  the  seeds. 

I.    GERANIUM,  Tourn. 

Herbs,  rarely  shrubs.  Leaves  with  stipules,  opposite  or 
alternate,  usually  cut  or  lobed.  Flowers  regular,  on  1-2- 
flowered  axillary  peduncles.  Sepals  and  petals  5.  Stamens 
10,  ripening  in  2  sets.  Ovary  5-lobed,  5-beaked  ;  stigmas  5. 

1.  G.  maculatum,   L.     WILD    CRANESBILL,    WILD    GERANIUM. 
Perennial,  with  an  erect,  hairy  stem,  12—18  in.  high.     Leaves  about 
5-parted,  marked  with  pale  blotches,  the  root-leaves  long-petioled. 
Flowers  large  (1  in.  or  more  in  diameter),  light  purple,  somewhat 
corymbed.      Petals   entire,  twice  as  long   as   the  calyx,   the   claw 
bearded.     Open  woods  and  thickets ;  common. 

2.  G.  robertianum.     HERB  ROBERT.     Annual  or  biennial.     Stems 
somewhat  hairy,  weak  and  spreading,  reddish.     Leaves  of  5  leaflets, 
the  latter  once  or  twice  pinnately  cut,  long-petiolecL    Flowers  light 
purple,  about  ^  in.  in  diameter,  streaked  with  dark  and  light  red. 
Claws  of  petals  smooth.     Damp  woods  and  ravines  E. 


H.    PELARGONIUM,  L'Her. 

Perennial  herbs  or  shrubs.  Leaves  with  stipules,  scented. 
Flowers  much  as  in  the  preceding  genus,  but  one  of  the 
sepals  hollowed  out  below  into  a  nectar-bearing  tube  extend- 
ing down  the  pedicel.  The  2  upper  petals  different  in  size  or 
shape  from  the  other  3.  Cultivated  from  the  Cape  of  Good 
Hope.  [Most  of  the  species  are  commonly,  though  not  quite 
correctly,  called  "  geraniums."  Only  a  few  of  the  commonest 
are  here  described.] 

1.  P.  peltatum,  Ait.    IVY  GERANIUM.    Stems  somewhat  prostrate 
and   trailing.      Leaves    somewhat    peltate,    smooth   or   nearly   so. 
Flowers  pink  or  white. 

2.  P.    zonale,    Willd.      HORSESHOE    GERANIUM.      Stem    erect, 
widely  branched,  woody  below.     Leaves  alternate,  opposite  or  some- 
times in  3's,  round  or   kidney-shaped,  palmately  veined,   crenate, 


DICOTYLEDONOUS   PLANTS  131 

downy,  usually  with  a  dark  zone  near  the  middle.  Flowers  in  a 
long  peduncled  umbel,  showy,  red  or  white,  often  double.  Number- 
less varieties  in  cultivation. 

3.  P.  graveolens,  Ait.     ROSE  GERANIUM.     Stem  erect  or  ascend- 
ing, densely  downy,  1-3  ft.  high.     Leaves  alternate,  palmately  lobed 
or  divided,  the  lobes  often  finely  dissected,  rolled  under  at  the  edges. 
Flowers  umbelled,  small,  light  purple  with  darker  veins  ;    whole 
plant  very  fragrant.     Common  in  cultivation. 

4.  P.    odoratissimum,    Ait.      NUTMEG     GERANIUM.      Branches 
crooked  and  straggling  from  a  very  short,  moderately  stout  main 
stem.     Leaves  small,  roundish  and  scalloped,  covered  with  velvety 
down,  very  fragrant.     Flowers  white,  inconspicuous,  on  short  pedi- 
cels, the  petals  hardly  longer  than  the  calyx. 


48.   OXALIDACE^.     WOOD-SORREL  FAMILY. 

Herbs  or  woody  plants.  Leaves  compound.  Flowers  in 
fives,  perfect,  regular,  hypogynous.  Stamens  10,  somewhat 
monadelphous  at  the  base.  Ovary  with  several  ovules  in 
each  cell.  Fruit  a  capsule. 

OXALIS,  L. 

Acid  herbs.  Leaves  radical  or  alternate,  with  or  without 
stipules,  usually  of  3  leaflets,  which  droop  at  night.  Sepals 
5.  Petals  5.  Stamens  10.  Ovary  5-lobed,  5-celled  ;  styles  5. 

1.  0.  Acetosella,  L.     WOOD-SORREL.     Stemless,  from  a  creeping, 
scaly  rootstock.     Leaves  all   radical,    long-petioled,    of   3    inversely 
heart-shaped  leaflets  ;  scape  slender,  2-5  in.  high,  1-flowered.    Flowers 
nearly  1  in.  in  diameter,  white,  veined  with  red  or  purple.     Cold 
woods  N. 

2.  0.   violacea,   L.      VIOLET  WOOD-SORREL.     Perennial  from  a 
bulbous   root,    stemless.      Leaves    long-petioled;    leaflets   inversely 
heart-shaped,    sometimes   slightly  downy,   often  with  a   dark  zone 
near  the  middle.     Scapes  usually  longer  than  the  petioles,  umbel- 
lately  4-10-flowered ;   pedicels  slender.     Flowers  violet-purple,  nod- 
ding.    Petals  obtuse,  2-3  times  as  long  as  the  sepals  ;  scapes  and 
petioles  4-5  in.  long.     Common  in  rich  woods.* 

[The  forms  with  small  yellow  flowers,  hitherto  referred  to  O.  cor- 
niculata,  belong  to  several  nearly  related  species  too  difficult  for  the 
beginner.] 


132  FOUNDATIONS   OF   BOTANY 


49.    TROP-^OLACE^).     INDIAN  CRESS  FAMILY. 

Smooth  and  tender  herbaceous  plants,  with  biting  juice,  often 
climbing  by  the  petioles  of  their  simple  leaves.  Leaves  alter- 
nate, without  stipules.  Peduncles  axillary,  1-fLowered.  Sepals 
3-5,  the  upper  one  with  a  long,  distinct  spur.  Petals  1-5, 
hypogynous,  not  always  all  alike.  Stamens  6-10,  perigynous, 
distinct.  Ovary  1,  3-cornered,  made  up  of  3-5  1-ovuled 
carpels;  style  1  ;  stigmas  3-5.  Fruit  not  opening. 

TROPJEOLUM,  L. 

Characteristics  of  the  genus  those  of  the  family  above 
given,  together  with  the  following  : 

Petals  usually  5,  clawed,  the  2  upper  inserted  at  the  mouth 
of  the  spur  and  unlike  the  3  lower  ones.  Stamens  8,  ripen- 
ing unequally,  the  filaments  curved.  Fruit  3-celled,  3-seeded. 
Cultivated  from  S.  A.  for  the  very  showy  flowers  and  the 
sharp-flavored  fruits,  which  are  often  pickled. 

1.  T.  majus,  L.  COMMON  NASTURTIUM.  Climbing  by  the  petioles 
6-8  ft.  (there  is  also  a  low  variety  which  does  not  climb).  Leaves 
roundish  but  more  or  less  6-angled,  peltate,  with  the  petiole  attached 
near  the  middle.  Flowers  varying  from  almost  white  to  nearly  black, 
but  commonly  crimson,  scarlet,  or  flame-color. 

50.   LINACEJE.     FLAX  FAMILY. 

.  Herbs,  shrubs,  or  trees.  Leaves  usually  alternate,  simple, 
entire,  sometimes  with  stipules.  Flowers  variously  clus- 
tered. Sepals  5,  distinct  or  coherent.  Petals  5,  hypogynous. 
Stamens  5,  monadelphous  below.  Pod  8-10-seeded,  with 
twice  as  many  cells  as  there  are  styles. 

LINUM,  Tourn. 

Herbs  or  small  shrubs,  with  tough,  fibrous  bark.  Leaves 
sessile.  Flowers  in  corymbs  or  panicles.  Sepals  5,  entire. 
Petals  5,  distinct  or  coherent  below,  falling  in  a  few  hours 
after  expanding. 


DICOTYLEDONOUS  PLANTS  133 

1.  L.  virginianum,  L.     WILD  FLAX.     Stem  rather  slender,  erect 
and  cylindrical ;  branches  cylindrical.     Leaves  small,  varying  from 
oblong  to  lanceolate  or  spatulate,  the  lower  often  opposite.     Flowers 
small,  yellow.      Capsules  flattened  at  right  angles  to  the  pedicels. 
Dry  woods  and  pastures. 

2.  L.   usitatissimum,   L.     COMMON    FLAX.      Stem    erect,    with 
corymbed  branches  at  the  top.    Leaves  narrowly  lanceolate.    Flowers 
handsome,  large,  blue.     Cultivated  for  the  fiber.     From  Europe ; 
introduced  here  to  some  extent. 


51.   RUTACE-ffi.     RUE  FAMILY. 

Shrubs  or  trees.  Leaves  alternate,  compound,  without 
stipules,  marked  with  translucent  dots.  Flowers  perfect  or 
variously  imperfect.  Sepals  and  petals  3-5  or  none  ;  petals 
hypogynous  or  perigynous  when  present.  Stamens  as  many 
or  twice  as  many  as  the  sepals,  inserted  on  the  glandular  disk. 
Pistils  2-5,  often  partially  united.  Fruit  a  capsule,  a  key- 
fruit,  or  in  the  important  genus  Citrus  (orange,  lemon,  lime, 
etc.,  not  here  described)  a  leathery-skinned  berry,  the  outer 
part  of  the  skin  containing  many  spherical  oil-cavities.* 

I.  XANTHOXYLUM,  L. 

Trees  or  shrubs  ;  bark,  twigs,  and  petioles  usually  prickly ; 
leaves  odd-pinnate,  marked  with  translucent  dots.  Flowers 
in  axillary  or  terminal  cymes  or  umbels,  monoecious  or 
dioecious.  Sepals  and  petals  3-5  or  none.  Stamens  3-5, 
hypogynous.  Pistils  2-5,  distinct.  Carpels  2-valved,  1-2- 
seeded.  Seeds  smooth  and  shining.* 

1.  X.  americanum,  Mill.  NORTHERN  PRICKLY  ASH,  TOOTHACHE- 
TREE.  A  prickly  shrub,  8-12  ft.  high,  with  aromatic  bark.  Leaves 
pinnately  compound;  leaflets  ovate-oblong.  Flowers  small  and 
greenish,  in  axillary  umbels,  appearing  before  the  leaves.  Petals 
4-5.  Pistils  3-5,  the  styles  slender.  Pods  rather  globose,  somewhat 
more  than  i  in.  in  diameter,  roughish,  borne  on  a  short  stalk  above 
the  receptacle,  with  a  strong  scent  of  lemon  and  tasting  at  first 
aromatic,  then  burning.  Rocky  woods,  ravines,  and  river  banks. 


134  FOUNDATIONS   OF  BOTANY 


H.    PTELEA. 

Shrubs  with  smooth  and  bitter  bark.  Leaves  with  3  leaflets. 
Flowers  in  terminal  cymes,  somewhat  monoecious.  Sepals 
3-6,  deciduous,  much  shorter  than  the  petals.  Stamens  4-5, 
longer  than  the  petals  and  alternate  with  them.  Pistillate 
flowers  producing  imperfect  stamens.  Ovary  compressed. 
2-celled.  Fruit  a  2-celled,  2-seeded,  broadly  winged  key.* 

1.  P.  trifoliata,  L.  HOP-TREE,  WAFER  ASH.  A  shrub  4-8  ft. 
high.  Leaves  long-petioled  ;  leaflets  oval  or  ovate,  acute,  obscurely 
serrate,  the  lateral  ones  oblique.  Cymes  compound.  Flowers 
greenish.  Stamens  mostly  4,  filaments  bearded,  key  about  1  in.  in 
diameter ;  wing  notched,  strongly  netted-veined.  Rocky  banks ;  often 
cultivated.* 


52.    POLYGALACEJE.     POLYGALA  FAMILY. 

Herbs  or  shrubs.  Leaves  alternate  or  nearly  opposite, 
without  stipules,  simple.  Flowers  irregular.  Sepals  unequal, 
the  2  inner  wing-shaped  and  petal-like.  Petals  3-5,  hypogy- 
nous,  the  2  lateral  ones  often  united  with  the  hooded  lower 
one  into  a  tube,  split  open  at  the  base  behind.  Stamens  8, 
filaments  united  into  a  split  sheath,  which  is  usually  adnate 
to  the  petals  ;  anthers  usually  opening  by  pores.  Ovary 
2-celled,  2-ovuled.  [A  difficult  family  for  the  beginner.] 

POLYGALA,  Tourn. 

Herbs  or  shrubs.  Flowers  racemed  or  spiked,  some  of  them 
often  cleistogamous.  Petals  adnate  below  to  the  stamen- 
sheath.  Anthers  opening  by  transverse  pores. 

1.  P.  paucifolia,  Willd.  FRINGED  POLYGALA,  BABIES'  TOES, 
MAY  WINGS.  A  low  perennial  herb,  with  branches  3-4  in.  high 
from  a  slender,  creeping  rootstock.  Lower  leaves  scattered,  small 
and  scale-like,  the  upper  ones  with  petioles,  crowded  near  the  tips  of 
the  branches,  ovate  or  nearly  so.  Flowers  of  two  kinds,  the  cleis- 
togamous whitish,  fertile,  borne  underground  along  the  rootstock,  the 
terminal  flowers  large  and  showy  (nearly  an  inch  long),  rose-purple, 
with  a  beautiful  fringed  crest.  Woods,  especially  N.  and  E. 


DICOTYLEDONOUS   PLANTS 


135 


2.  P.  Senega,  L.  SENECA  SNAKEROOT.  A  perennial  herb,  with 
several  erect  stems  arising  from  stout,  hard,  knotty  rootstocks. 
Leaves  lanceolate,  oblong  or  lance-ovate,  sessile.  Flowers  all  alike, 
small,  white,  in  solitary  close  spikes.  Rocky  woods. 


53.   EUPHORBIACEJE.     SPURGE  FAMILY. 

Herbs,  shrubs,  or  trees,  usually  with  a  milky,  more  or  less 
acrid  and  sometimes  poisonous  juice.  Flowers  mostly  apeta- 
lous,  monoecious  or  dioecious  (Fig.  16).  Ovary  usually  3-celled, 
with  1  or  2  ovules  in  each  cell ;  stigmas  as  many  as  the 


C 


FIG.  16.  —  Euphorbia  corollata. 


A,  flower-cluster  with  involucre,  the  whole  appearing  like  a  single  flower ;  £,  a 
single  staminate  flower  ;  C,  immature  fertile  flower,  as  seen  after  the  removal  of 
the  sterile  flowers  ;  i,  involucre  ;  s,  stigmas. 

cells  or  twice  as  many.  Fruit  a  3-lobed  capsule.  Seeds  con- 
taining fleshy  or  oily  endosperm  (Part  I,  Fig.  2).  Most  of 
the  family  are  natives  of  hot  regions,  many  of  them  of  pecu- 
liar aspect  from  their  adaptation  to  life  in  dry  climates. 
[The  family  is  too  difficult  for  the  beginner  in  botany  to 
determine  many  of  its  genera  and  species  with  certainty,  but 
a  few  are  described  below.] 


136  FOUNDATIONS   OF   BOTANY 


I.    EUPHORBIA,  L. 

Herbs  or  shrubs,  with  milky  juice,  often  poisonous. 
Flowers  monoecious,  enclosed  in  a  4-5-lobed  involucre,  which 
is  often  showy  and  resembles  a  calyx  or  corolla,  usually  bear- 
ing large  glands  at  its  notches.  Sterile  flowers  many,  borne 
inside  the  involucre  at  its  base  (Fig.  16,  A),  each  consisting  only 
of  a  single  stamen  attached  by  a  joint  to  a  pedicel  which 
looks  like  a  filament.  Fertile  flower  standing  alone  at  the 
center  of  the  involucre  (Fig.  16,  (7)  (soon  pushed  out  by  the 
growth  of  its  pedicel),  consisting  only  of  a  3-lobed  and 
3-celled  ovary,  3  2-cleft  styles,  and  6  stigmas.  Pod  3-celled 
and  3-seeded. 

A.  Cultivated  shrubs. 

1.  E.    splendens,  Bojer.      CROWN    OF    THORNS.      An   extremely 
prickly    shrub,   with    many  erect,   few-leaved    branches.      Leaves 
obovate  or  obovate-spatulate,  mucronate,  entire,  each  with  two  very 
sharp  prickles  (longer  than  the  petiole)  as  stipules.     Peduncles  long, 
sticky,  each  bearing  2-4  objects,  which  appear  to  be  showy  scarlet 
flowers,  but  which  are  actually  2-bracted  involucres  containing  the 
true  flowers.    Involucral  scales  somewhat  kidney-shaped,  mucronate. 
Flowering  all  the  year  round.     Cultivated  in  greenhouses.     From 
Mauritius. 

B.  Herbs  with  rather  showy  white  flower-clusters. 

2.  E.    corollata,   L.      FLOWERING    SPURGE.      Perennial.      Stem 
erect,  umbellately  branched  above,  smooth  or  downy,  1-3  ft.  high. 
Leaves  of  the  stem  alternate,  those  of  the  branches  usually  opposite 
or  whorled,  rather  thick,  oval   to  narrowly   oblong,  pale  beneath, 
usually  slightly   downy.       Flowering   branches    repeatedly  forked ; 
involucres  terminal  and  in  the  forks  of    the  branches,  peduncled; 
glands  4-5,  oblong,  green  ;  appendages  white  and  petal-like,  showy. 
Capsule  erect,  seed  smooth  or  faintly  pitted.     Common  in  dry,  open 
woods. 

C.  Herbs:  No.  3  a  native  species,  No.  4  cultivated  from  Europe  or 
escaping  from  gardens.    Flower-clusters  in  umbels  not  white.     Involucre 
4  or  5  lobed,  each  lobe  with  a  gland. 

3.  E.  dictyosperma,  Fischer  and  Mayer.     Annual.     Stem  slender, 
8-18  in.  high,  erect.     Stem-leaves  oblong-spatulate  to  obovate,  ser- 
rate ;  floral  ones   roundish-ovate,  somewhat  heart-shaped.     Flower- 
cluster  a  compound  umbel,  the  rays  once  or  twice  3-forked,  then 
2-forked.     Seeds  covered  with  a  network.     Prairies  and  roadsides. 


DICOTYLEDONOUS  PLANTS  137 

4.  E.  Cyparissias,  L.     CYPRESS  SPURGE,  CYPRESS,  GRAVEYARD 

Moss.  A  perennial,  in  dense  clusters  6-12  in.  high  from  running 
rootstocks.  Leaves  much  crowded,  all  sessile,  the  stem-leaves  linear, 
floral  ones  broadly  heart-shaped.  Flower-cluster  a  simple,  many- 
rayed  umbel.  Glands  crescent-shaped.  Cemeteries,  roadsides,  etc., 
escaped  from  cultivation;  also  cultivated  in  old  gardens.  From 
Europe. 

II.    JATROPHA,  L. 

Shrubs  or  herbs.  Leaves  alternate.  Flowers  monoecious, 
staminate  and  pistillate  intermixed  in  the  cymes,  apetalous. 
Calyx  large,  white,  5-lobed,  corolla-like.  Stamens  numerous, 
usually  monadelphous.  Ovary  usually  3-celled,  3-seeded  ; 
styles  3,  united  at  the  base,  several-parted.1* 

1.  J.  stimulosa,  Michx.  SPURGE  NETTL^.  Perennial  herbs  armed 
with  stinging  hairs  ;  stems  erect,  branched,  bright  green  with  white 
lines,  8-15  in.  high.  Leaves  long-petioled,  deeply  palmately  3-5- 
lobed,  the  lobes  irregularly  cut  and  toothed,  often  mottled.  Sepals 
white,  spreading.  Seeds  oblong,  smooth,  mottled.  In  dry  woods  S.* 


54.   ANACARDIACEJE.     SUMAC  FAMILY. 

Trees  or  shrubs,  with  resinous,  acrid,  or  milky  sap.  Leaves 
simple,  of  3  leaflets  or  pinnately  compound,  alternate,  with- 
out stipules.  Flowers  perfect  or  imperfect,  small.  Calyx 
3-5-parted,  persistent.  Petals  3-5  or  wanting.  Stamens  as 
many  as  the  sepals  or  sometimes  twice  as  many,  inserted  in 
the  base  of  the  calyx,  distinct.  Ovary  free,  1-celled,  styles 
1-3.  Fruit  a  1-seeded  stone-fruit.* 

RHUS,  L. 

Trees  or  shrubs.  Leaves  of  3  leaflets  or  odd-pinnate. 
Flowers  in  spikes  or  panicles.  Calyx  mostly  5-parted. 
Petals  and  stamens  5.  Pistil  1,  sessile  ;  styles  3,  terminal. 
Fruit  small,  smooth  or  downy.* 

1.  R.  glabra,  L.  SUMAC.  A  shrub  or  small  tree,  sometimes 
25-30  ft.  high  ;  branches  downy.  Leaves  odd-pinnate,  main  midrib 
downy  and  wing-margined  ;  leaflets  9-21,  ovate-lanceolate,  acute  at 
the  apex,  inequilateral,  entire  or  slightly  toothed,  smooth  and  green 


138  FOUNDATIONS  OF  BOTANY 

above,  pale  and  downy  beneath.    Panicle  often  large  and  spreading  ; 
flowers  somewhat  monoecious.    Fruit  red,  hairy,  acid.    Open  woods.* 

2.  R.  typhina,  L.     STAGHORN  SUMAC.     A   small  tree,  20-40  ft. 
high;  branches  and  petioles  closely  velvety-hairy.     Leaves  odd-pin- 
nate, leaflets    17-27,  lanceolate-oblong,  taper-pointed   at   the  apex, 
very  obtuse  at  the  base,  sharply  serrate,  smooth  above,  pale   and 
downy  beneath.     Flowers  somewhat  monoecious,  in  dense  terminal 
panicles.     Fruit  red,  with  crimson  hairs.     Dry  hillsides  N".  and  E.* 

3.  R.  Toxicodendron,  L.     POISON  VINE,  POISON  IVY,  MERCURY, 
BLACK  MERCURY.      Stem  a  woody  vine  climbing  high  by  aerial 
rootlets,  or  sometimes  short  and  erect.     Leaves  petioled,  of  3  leaflets, 
downy;     leaflets  ovate  or   oval,  taper-pointed,  entire    or    somewhat 
dentate,  often  angled  or  lobed.     Flowers  dioecious,  in  loose  axillary 
panicles.     Fruit  nearly  white,  smooth.    Common  in  open  woods  and 
along  fences.     Plant  poisonous  to  the  touch.* 

4.  R.  venenata,  L.     POISON  SUMAC,  POISON  DOGWOOD.     A  very 
smooth  shrub  with  gray  bark,   6-18  ft.   high.      Leaves  large  and 
glossy,  with  7-13  obovate-oblong,    entire    leaflets.     Flower-clusters 
loosely-flowered,  axillary  panicles.     Fruit   smooth,  greenish-yellow. 
Swamps  and  wet  openings  in  woods  N.  and  E.     Plant  more  poison- 
ous than  the  preceding  species, 


55.   AQUIFOLIACE^E.     HOLLY  FAMILY. 

Trees  or  shrubs.  Leaves  simple,  alternate,  petioled ;  stip- 
ules small  or  wanting.  Flowers  small,  greenish,  clustered 
or  solitary  in  the  axils,  usually  dioecious.  Calyx  4-9-parted. 
Petals  4-9,  somewhat  united  at  the  base.  Stamens  inserted 
in  the  tube  of  the  corolla  and  alternate  with  its  lobes.  Ovary 
free,  4-9-celled,  with  a  single  ovule  in  each  cell.  Fruit  a 
berry-like  stone-fruit,  4-9-seeded.* 

ILEX,  L. 

Small  trees  or  shrubs.  Leaves  usually  leathery,  often  per- 
sistent and  evergreen ;  stipules  minute.  Flowers  axillary, 
4-9-parted,  the  fertile  often  solitary  and  the  staminate  clus- 
tered. Fruit  a  stone-fruit  with  4-9  nutlets.* 

1.  I.  opaca,  Ait.  HOLLY.  Trees  with  smooth,  light-colored  bark, 
and  hard,  very  white  wood ;  young  twigs  downy.  Leaves  leathery, 
oval  or  ovate,  margin  prickly-toothed,  dark  green  and  shining 


DICOTYLEDONOUS  PLANTS  139 

above,  paler  and  sometimes  slightly  downy  beneath.  Peduncles 
short,  bracted.  Flowers  4-parted,  staminate  flowers  in  small  cymes, 
the  pistillate  usually  solitary.  Fruit  bright  red.  Damp,  sandy  soil 
E.  and  S.* 

2.  I.  decidua,  Walt.      DECIDUOUS    HOLLY.      Small  trees;  twigs 
smooth.     Leaves  thin,  obovate,  obtuse    or  sometimes  acute  at  the 
apex,   scalloped,   smooth,   deciduous.      Flowers   in   sessile  clusters, 
4-6  parted.     Fruits  very  numerous,  bright  red.     On  low  ground  S.* 

3.  I.  verticillata,  Gray.    BLACK  ALDER,  WINTERBERRY.  *  A  much- 
branched  shrub  6-8  ft.  high.     Leaves  thin,  oval  or  obovate,  taper- 
pointed,  serrate,  1^-2   in.    long.     Flowers   greenish-white,  on  very 
short  peduncles.     Fruit  bright  red,  1,  2,  or  3  in  a  leaf -axil,  remain- 
ing long  after  the  leaves  have  fallen.     Swampy  ground  and  damp 
woods  and  thickets. 


56.   CELASTRACEJE.     STAFF-TREE  FAMILY. 

Trees  or  shrubs,  sometimes  climbing.  Leaves  simple,  oppo- 
site or  alternate.  Flowers  small,  in  cymes.  Calyx  small, 
4-5-lobed,  persistent.  Petals  4-6,  short.  Stamens  4-6, 
alternate  with  the  petals  and  inserted  with  them  on  a  disk. 
Ovary  sessile,  3-5-celled  ;  style  entire  or  3-5-cleft ;  ovules  2 
in  each  cell.  Seeds  usually  covered  with  an  appendage  (aril) 
growing  from  the  hilum. 

I.    CELASTRUS,  L. 

A  woody,  twining  shrub.  Leaves  alternate.  Flowers 
dioecious  or  somewhat  monoecious,  small,  greenish,  clustered 
at  the  ends  of  the  branches.  Pod  3-celled,  3-valved,  looking 
like  an  orange-colored  berry,  which  on  opening  shows  the 
scarlet  arils  of  the  seeds. 

1.  C.  scandens,  L.  WAX-WORK,  CLIMBING  BITTERSWEET. 
Climbing  10-15  ft.  Leaves  ovate-oblong,  2-4  in.  long,  finely  ser- 
rate, taper-pointed.  In  thickets  and  along  fences,  also  planted  for 
the  showy  scarlet  seeds,  which  retain  their  color  for  many  months. 

H.    EUONYMUS,  Tourn. 

Shrubs  with  4-angled  branches.  Leaves  opposite.  Flowers 
in  axillary,  peduncled  cymes,  purplish  or  greenish,  small. 


140  FOUNDATIONS   OF  BOTANY 

Sepals  and  petals  4-5,  spreading.  Stamens  as  many  as  the 
petals,  short.  Ovary  3-5-celled,  with  2  ovules  in  each  cell. 
Seeds  enclosed  in  a  red,  fleshy  pulp.* 

1.  E.    americanus,    L.      STRAWBERRY   BUSH.     A    shrub  3-8  ft. 
high.      Leaves   short-petioled,   ovate   to   ovate-lanceolate,    acute  or 
taper-pointed  at  the  apex,  finely  serrulate,  smooth  or  slightly  hairy. 
Peduncles  axillary,  slender,  1-3-nowered.    Flowers  greenish.    Capsule 
3-5-angled,  warty.     In  low,  shady  woods. 

2.  E.  atropurpureus,  Jacq.     WAHOO.     A  tree-like  shrub  10-15  ft. 
high.     Leaves  oval  to  ovate,  taper-pointed,  finely  serrulate,  minutely 
downy  petioles  £-f  in.  long.     Peduncles  slender,  3-forked,  several- 
flowered.      Flower    purplish ;    capsule    deeply    3-5-lobed,    smooth. 
River  banks. 


57.    STAPHYLEACE.35.     BLADDER-NUT  FAMILY. 

Shrubs.  Leaves  pinnately  compound,  with  stipules,  and 
the  leaflets  with  little  individual  stipules  (stipels).  Flowers 
regular  and  perfect.  Calyx-lobes  5.  Petals  5,  inserted  in  or 
around  a  saucer-shaped  disk.  Stamens  5,  alternate  with  the 
petals,  perigynous.  Ovary  2-3-celled,  with  the  carpels  more 
or  less  distinct ;  ovules  several ;  styles  2-3,  cohering  some- 
what below.  Fruit  usually  1-few-seeded. 

STAPHYLEA,  L. 

Calyx  deeply  5-parted,  the  lobes  appearing  like  separate 
sepals,  erect.  Petals  spatulate,  borne  on  the  rim  of  the  thick 
disk.  Pod  large,  papery,  3-celled,  finally  opening  at  the  top. 
Seeds  1-4  in  each  cell,  bony. 

1.  S.  trifolia,  L.  AMERICAN  BLADDER-NUT.  A  shrub  6-12  ft. 
high,  with  smooth,  slender,  greenish  striped,  at  length  gray,  branches. 
Leaves  long-petioled,  with  3  ovate,  taper-pointed,  finely  serrate  leaf- 
lets. Damp  thickets. 

58.   ACERACE^).     MAPLE  FAMILY. 

Trees  or  shrubs,  with  abundant,  often  sugary  sap.  Leaves 
opposite,  simple  and  palinately  lobed,  or  pinnate,  without 


DICOTYLEDONOUS   PLANTS  141 

stipules.  Flowers  regular,  mostly  somewhat  monoecious  or 
dioecious,  in  axillary  and  terminal  cymes  or  racemes.  Calyx 
4-9-parted.  Petals  as  many  as  the  lobes  of  the  calyx  or 
none.  Stamens  4-12,  hypogynous.  Ovary  2-celled  ;  styles  2. 
Fruit  a  double  key.* 

ACER,  Tourn. 
Characteristics  of  the  genus  as  above  given  for  the  family. 

1.  A.  saccharinum,  L.   (A.  dasycarpum,  Ehrh.).     WHITE  MAPLE, 
RIVER  MAPLE.     A  tall  tree  with  the  main  branches  slender  and 
rather  erect.     Leaves  very  deeply  5-lobed,  with  the  notches  rather 
acute,  silvery-white,  and  when  young  downy  on  the  lower  surface, 
the  divisions  narrow,  coarsely  cut  and  toothed.     Flowers  greenish, 
in  umbel-like  clusters,  appearing  long   before   the   leaves.      Petals 
absent.     Fruit  woolly  at  first,  then  smooth,  with  diverging  wings, 
the  whole  2-3  in.  long.     Common  on  river  banks  S.  and  W.,  also 
planted  for  a  shade-tree,  but  not  safe,  as  the  branches  are  easily 
broken  off  by  the  wind. 

2.  A.  rubrum,  L.     RED  MAPLE.     A  small  tree  with  red  or  purple 
twigs.     Leaves  simple,  broadly  ovate,  palmately  3-5-lobed  or  some- 
times  merely    serrate  or    cut-toothed,    taper-pointed   at   the    apex, 
rounded  or  heart-shaped  at  the  base,  smooth  or  downy,  becoming 
bright  red  in  autumn.    Flowers  appearing  before  the  leaves  on  erect, 
clustered  pedicels.     Petals  red  or  yellow,  oblong  or  linear.     Fruiting 
pedicels  elongated,  and  drooping.     Key  red,  smooth,  wings  about  an 
inch  long.     Swamps  and  river  banks  E.* 

3.  A.  saccharum,  Marsh  (A.  saccharinum,  Wang.).    SUGAR  MAPLE. 
A  large   tree.     Leaves    simple,  palmately  lobed,  truncate  or  heart- 
shaped  at  the  base,  lobes  sinuate-toothed  and  acuminate,  pale  and 
slightly  downy  beneath.      Flowers  appearing  with  the  leaves,   on 
clustered   drooping  pedicels.      Calyx   bell-shaped,   fringed.      Petals 
none.     Keys  smooth,   wings  about  1-1^  in.  long.     In  cold  woods, 
more  abundant  northward.     The  sap  of  this  tree  is  the  principal 
source  of   maple   sugar,  and  some  forms  of  the  tree  produce  the 
curled  maple  and  bird's-eye  maple  used  in  cabinet-making.* 

4.  A.  Pseudo-Platanus,  L.     SYCAMORE  MAPLE.    Easily  recognized 
by  its  drooping  clusters  of  rather  large  green  flowers,  which  appear 
with  the  leaves.     Cultivated  from  Europe. 

5.  A.    platanoides,   L.      NORWAY    MAPLE.      A  large   tree,  with 
milky  sap,  which  exudes  from  broken  shoots   or  leafstalks  in  the 
spring.     Cultivated  from  Europe  ;  a  very  desirable  shade-tree. 

6.  A.  Negundo,  L.     Box  ELDER.    A  small  tree.    Leaves  opposite, 


142  FOUNDATIONS   OF   BOTANY 

pinnately  3-5-foliate ;  leaflets  ovate,  lobed,  toothed  or  entire,  downy 
when  young.  Flowers  dioecious,  appearing  from  lateral  buds  before 
or  with  the  leaves ;  the  staminate  on  long  and  drooping  pedicels, 
the  pistillate  in  drooping  racemes.  Keys  smooth,  l-l£  in.  long. 
River  banks.  Often  cultivated  as  a  quick-growing  shade-tree.* 


59.    HIPPOCASTANACEJE.     BUCKEYE  FAMILY. 

Trees  or  shrubs.  Leaves  opposite,  long-petioled,  palmately 
compound.  Flowers  showy,  somewhat  monoecious,  in  termi- 
nal panicles.  Calyx  5-lobed,  oblique.  Petals  4-5,  unequal. 
Stamens  5-8,  hypogynous.  Pistil  1  ;  ovary  3-celled,  2  ovules 
in  each  cell;  style  slender.  Fruit  a  1-3-celled,  leathery 
capsule,  1-3-seeded.  Seeds  with  a  large  scar.* 

JESCULUS,  L. 

Characteristics  of  the  genus  as  above  given  for  the  family. 

1.  M.  Hippocastanum,  L.      HORSE-CHESTNUT.     A  round-topped 
tree  with  frequently  forking  branches  and  stumpy  twigs.     Leaves 
very  large,  with  7  straight-veined  leaflets.     Flowers  large  and  showy. 
Corolla  open  and  spreading,  of  5  white  petals,  spotted  with  purple 
and  yellow.    Stamens  with  long,  curved  filaments.    Fruit  large,  cov- 
ered with  stout,  soft  prickles  when  young.     Cultivated  from  Asia. 

2.  JE.  glabra,  Willd.     OHIO  BUCKEYE.     A  large  tree,  not  unlike 
a  horse-chestnut.     Leaflets  generally  5.     Flowers  small.     Corolla  of 
4  upright,  pale  yellow  petals.     Stamens  curved,  about  twice  as  long 
as  the  petals.     Fruit  prickly  at  first.     River  banks. 

3.  M.  flava,  Ait.      SWEET  BUCKEYE.      Varying  in  size  from  a 
low  shrub  to  a  tall  tree.     Leaves  with  5-7  leaflets.     Flowers  in  a 
short,  dense  panicle.     Petals  4,  in  2  unlike  pairs,  bending  inward, 
blades  of  the  longer  pair  very  small.     Fruit  not  prickly.     Woods 
W.  and  S. 

4.  JE.  Pavia,  L.    RED  BUCKEYE.    Shrubs ;  stems  erect,  branched, 
4-8  ft.  high.     Leaflets  usually  5,  lanceolate  to  narrowly  oval,  taper- 
pointed  at  both  ends,  finely  serrate,  smooth  or  nearly  so.     Flowers 
in  dense,  erect  panicles,  bright  red.     Stamens  rather  longer  than 
the  petals.     Fruit  nearly  smooth.     Common  in  open  woods.* 


DICOTYLEDONOUS   PLANTS  143 


60.    BALSAMINACEJE.     BALSAM  FAMILY. 

Tender,  fleshy-stemmed,  annual  herbs.  Leaves  simple,  with- 
out stipules.  Flowers  perfect,  irregular.  Sepals  usually  3, 
the  largest  one  with  a  spur.  Petals  3.  Stamens  5,  distinct 
or  nearly  so.  Ovary  5-celled,  bursting  when  ripe  into  5 
valves. 

IMPATIENS,  L. 

Characteristics  of  the  genus  those  above  given  for  the 
family.  Fruit  a  capsule  (very  fleshy  in  our  species),  which 
when  ripe  bursts  open  with  considerable  force,  throwing  the 
seeds  about. 

1.  I.  aurea,  Muhl.  (I.  pallida,  Nutt.).    WILD  BALSAM.     LADY'S- 
SLIPPER.     Stem  3-5  ft.  high,  branching.     Leaves  oblong-ovate,  2-6 
in.  long,  the  lower  often  loiig-petioled,  the  upper   nearly    sessile. 
Peduncles  axillary,   1-3  in.  long,  slender,  2-5  flowered.      Flowers 
pale  yellow,  slightly  dotted  with  brownish-red.     Sac   of  the  large 
sepal  broader  than  it  is  long,  ending  in  a  recurved  spur  about  ^  in. 
long.     Damp,  shaded  ground,  not  very  common. 

2.  I.  biflora,  Walt.   (I.  fulva,  Nutt.).      WILD  BALSAM,   LADY'S- 
SLIPPER,  JEWEL  WEED,  SNAP  WEED,  KICKING  COLT.    Stem  2-4  ft. 
high,  branching.     Leaves  rhombic-ovate,  1-4  in.  long.     Peduncles 
about  1  in.  long,  generally  2-3-flowered.     Flowers  orange-color,  with 
many  pretty,  large,  reddish-brown  spots.     Sac  longer  than  it  is  broad, 
ending  in  a  recurved  spur  about  ^  in.  long.     Damp,  shaded  ground, 
commoner  than  No.  1  and  usually  blossoming  earlier. 


61.   RHAMNACE-/E.     BUCKTHORN  FAMILY. 

Trees  or  shrubs.  Leaves  simple,  often  3-5-nerved ;  stipules 
small.  Flowers  small,  sometimes  imperfect,  green  or  yellow. 
Calyx  4-5-lobed.  Petals  4,  5,  or  absent,  inserted  on  a  disk  at 
the  throat  of  the  calyx,  very  small,  hooded,  usually  with 
claws.  Stamens  4-5,  inserted  with  the  petals  and  opposite 
them,  often  enclosed  by  the  petals  ;  filaments  awl-shaped  ; 
anthers  small,  versatile.  Ovary  3-celled,  3-ovuled. 


144  FOUNDATIONS   OF   BOTANY 


I.    BERCHEMIA,  Necker. 

Shrubs  ;  stems  twining  or  erect.  Leaves  alternate,  promi- 
nently pinnate-veined,  stipules  minute.  Flowers  in  axillary 
or  terminal  panicles,  or  rarely  solitary.  Calyx-tube  hemi- 
spherical, 5-lobed.  Petals  5,  sessile,  concave,  as  long  as  the 
calyx.  Ovary  2-celled,  half-inferior  ;  stigmas  2.  Fruit  an 
oval,  2-seeded  stone-fruit.* 

1.  B.  volubilis,  DC.  SUPPLE-JACK,  RATTAN-VINE.  Woody,  often 
twining  high  ;  older  bark  yellowish,  twigs  purple,  wood  very  tough. 
Leaves  ovate  or  oval,  acute  or  obtuse,  cuspidate  at  the  apex, 
rounded  at  the  base,  wavy  on  the  margins,  green  above,  pale  beneath. 
Flowers  in  small  panicles.  Fruit  purple.  In  moist  woods  and  along 
streams  S.* 

H.    RHAMNUS,  L. 

Leaves  alternate,  deciduous.  Flowers  in  small,  axillary 
cymes,  often  imperfect.  Petals  4-5  or  wanting.  Stamens  4 
or  5,  very  short.  Stone-fruit,  2-4-seeded. 

1.  R.  lanceolata,  Pursh.     A  tall  shrub.     Leaves  with  short  peti- 
oles, taper-pointed  or  somewhat  obtuse,  very  variable  in  size,  smooth 
or  nearly  so    above,   more  or  less   downy  beneath,  finely  serrate. 
Flowers  2  or  3  together  in  the  axils,  greenish,  about  £  in.  in  diame- 
ter, usually  dioecious,  appearing  at  the  same  time  as  the  leaves. 
Calyx  4-lobed.     Petals  4.     Stamens  4.     Fruit  black,  about  £  in.  in 
diameter.     Hills  and  river  banks. 

2.  R.  caroliniana,  Walt.     CAROLINA  BUCKTHORN.     A  small  tree 
with  black  bark  and  very  hard  wood  ;  twigs  finely  downy.     Leaves 
alternate,  prominently  veined,  elliptical  to  broadly  oval,  entire  or 
obscurely  serrate,  smooth  or  sometimes  downy  below  ;  petioles  slen- 
der, downy.     Flowers  in  axillary,  peduncled  umbels ;  petals  minute. 
Fruit  globose,  £-£  in.  in  diameter,  3-seeded.     Seeds  smooth.     On 
river  banks.* 

m.    CEANOTHUS,  L. 

Shrubs.  Leaves  alternate,  petioled.  Flowers  perfect,  in 
terminal  panicles  or  corymbs  formed  of  little  umbel-like  clus- 
ters. Calyx-tube  top-shaped  or  hemispherical,  with  a  5-lobed 
border.  Petals  5,  with  hoods,  on  slender  claws.  Stamens  5, 
filaments  long  and  thread-like.  Fruit  dry,  3-lobed,  splitting 
when  ripe  into  3  carpels. 


DICOTYLEDONOUS  PLANTS  145 

1.  C.  americanus,  L.  NEW  JERSEY  TEA,  RED  ROOT.  Shrub, 
with  many  branching  stems,  1-3  ft.  high,  from  a  deep  red  root. 
Leaves  1-3  in.  long,  ovate  or  nearly  so,  acute  or  taper-pointed  at  the 
tip,  obtuse  or  somewhat  heart-shaped  at  the  base,  downy  beneath, 
serrate,  3-nerved.  Flowers  small,  white. 

62.   VITACE^:.     VINE  FAMILY. 

Shrubs,  with  the  stem  swollen  at  the  insertion  of  the  peti- 
oles and  climbing  by  tendrils  borne  opposite  the  leaves. 
Leaves  alternate,  with  stipules  simple  or  compound.  Flowers 
small,  greenish,  generally  in  clusters,  borne  in  similar  posi- 
tions to  the  tendrils,  hypogynous  or  nearly  so.  Sepals,  petals, 
and  stamens  4-5.  Carpels  2,  each  2-ovuled.  Calyx  very 
small.  Corolla  deciduous,  the  petals  often  hooded.  Stamens 
opposite  the  petals.  A  disk  inside  the  calyx  bears  nectar  and 
its  lobes  alternate  with  the  stamens.  Fruit  a  berry. 

I.    VITIS,Tourn. 

Climbing  woody  vines ;  stems  with  tumid  joints,  climbing 
by  tendrils  opposite  some  of  the  leaves.  Leaves  simple, 
palmately  veined  or  lobed  ;  stipules  small,  soon  deciduous. 
Flowers  mostly  somewhat  monoecious  or  dioecious.  Petals 
often  united  at  the  apex  and  not  expanding.  Stamens  in- 
serted between  the  lobes  of  the  disk.  Ovary  usually  2-celled, 
4-ovuled.  Fruit  juicy,  1-4-seeded.* 

1.  V.    labrusca,  L.     Fox  GRAPE.     Stems  climbing  high,  often 
1  ft.  or  more  in  diameter  ;  bark  shreddy,  coming  off  in  long  strips, 
young  branches  woolly.     Leaves  broadly  heart-shaped,  more  or  less 
deeply   3-5-lobed,    mucronate-dentate,    very    woolly    when    young, 
becoming  smooth  above.     Panicles  of  pistillate  flowers  compact,  of 
staminate  flowers  looser.     Fruit  about  £  in.  in  diameter,  dark  pur- 
ple or  sometimes  nearly  white.    In  rich  woods  E.,  S.,  and  SW.    Many 
of  the  cultivated  varieties,  Concord,  Niagara,  etc.,  have  been  devel- 
oped from  this  species.* 

2.  V.  aestivalis,  Michx.     SUMMER  GRAPE.     Stem  climbing  high  ; 
bark  shreddy.     Leaves   broadly  heart-shaped,    3-5-lobed,  the  lobes 
dentate,  notches  rounded,  white-woolly  when   young,  often  nearly 
smooth  when   old ;  tendrils  or  paniqles  opposite  2  out  of  every  3 


146  FOUNDATIONS   OF   BOTANY 

leaves,  panicles  long  and  slender.  Fruit  dark  blue,  small,  very  acid. 
In  rich  woods  E.  and  S.* 

3.  V.    cordifolia,    Michx.      FROST     GRAPE,    CHICKEN    GRAPE. 
Leaves  rather  smooth,  thin,  and  shining,  either  not  lobed  or  some- 
what 3-lobed,  heart-shaped,  with  the  notch  at  the  base  deep  and 
acute,  taper-pointed,  with  large,  sharp  teeth.     Flower-clusters  large 
and  loose.     Grapes  shining  black,  very  sour,  not  ripening  until  after 
frosts ;  seeds   1  or  2,  rather  large.     Moist  thickets  and  banks  of 
streams  S. 

4.  V.  rotundifolia,  Michx.     MUSCADINE  GRAPE.     Stem  climbing 
high ;  joints  short ;  bark  not  shreddy  ;  wood  very  hard,  often  pro- 
ducing long,   aerial  roots.     Leaves  orbicular,  heart-shaped  at   the 
base,    coarsely  toothed,    nearly   or    quite   smooth.     Panicle    small. 
Grapes  few  in  a  cluster,  large.     The  original  form  of  the  Scupper- 
nong  grape  S.* 

II.    AMPELOPSIS,  Michx. 

Woody  vines,  climbing  by  tendrils  and  rootlets.  Leaves 
palmately  compound.  Flowers  in  compound  cymes,  perfect 
or  somewhat  monoecious.  Petals  5,  distinct,  spreading  ;  disk 
none.  Stamens  5.  Ovary  2-celled,  4-ovuled.  Fruit  a  1-4- 
seeded  berry,  not  edible.* 

1.  A.   quinquefolia,   Michx.      VIRGINIA   CREEPER.      WOODBINE. 

Stem  usually  climbing  high,  but  sometimes  short  and  prostrate, 
often  producing  many  adventitious  aerial  roots  which  assist  the  vine 
in  holding  to  a  support ;  tendrils  usually  terminating  in  flat,  adhesive 
disks.  Leaves  palmately  compound,  of  5  oval  leaflets,  coarsely  and 
unevenly  toothed  above,  usually  entire  below,  smooth  or  slightly 
downy.  Cymes  large  and  spreading  when  mature  ;  pedicels  red. 
Berries  small,  dark  blue.  Common  in  rich  woods.* 

2.  A.  tricuspidata,  Sieb.  and  Zucc.     JAPANESE  IVY,  BOSTON  IVY. 
A  freely  branching,  hardy  climber.     Tendrils  numerous,  branching 
with  closely  adhesive  disks.     Leaves  occasionally  with  3  leaflets,  but 
usually  with  only  one,  which  is  jointed  with  the  main  petiole  and 
in  autumn  falls  before  the  petiole ;  leaflet  3-lobed  or  only  scalloped, 
roundish-ovate   or  heart-shaped,  rather   thick  and  shining.      Culti- 
vated from  Japan. 


63.    TILLAGES.      LINDEN  FAMILY. 

Trees    or   shrubs,   rarely   herbs.       Leaves    alternate,   with 
stipules.     Flowers   perfect  in   cymes,  the  latter  usually  in 


DICOTYLEDONOUS   PLANTS  147 

corymbs  or  panicles.  Sepals  5.  Petals  5  or  fewer  or  wanting. 
Stamens  many,  inserted  on  a  swollen  disk.  Ovary  2-10-celled, 
with  1  or  more  ovules  in  each  cell.  Fruit  1-12-celled,  dry  or 
berry-like. 

TILIA,  Tourn. 

Trees  with  rough  gray  bark  on  the  trunk ;  bark  of  the  twigs 
smooth,  lead-colored ;  wood  white  and  soft.  Leaves  cordate, 
usually  inequilateral.  Cymes  axillary  or  terminal,  peduncles 
adnate  to  a  large,  prominently  veined  leaf-like  bract.  Flowers 
yellowish-white.  Sepals  5.  Petals  5.  Stamens  many,  in  5 
groups.  Ovary  5-celled,  with  2  ovules  in  each  cell  ;  stigma 
5-lobed.  Capsule  1-celled,  1-2-seeded  ;  peduncle  and  bract 
deciduous  with  the  matured  fruit,  the  bract  forming  a  wing 
by  which  the  fruit  is  often  carried  to  a  considerable  distance.* 

1.  T.  pubescens,  Ait.     BASSWOOD.    A  tree  of  medium  size  ;  leaves 
ovate,   acuminate    at   the   apex,  obtuse   and   oblique   at   the  base, 
mucronate-serrate,  woolly  on  both  sides  or  smooth  above  when  old  ; 
flowers  fragrant,  floral  bract  2-3  in.  long,  usually  rounded  at  the 
base.     Fruit  globose,  about  \  in.  in  diameter.     In  rich  woods.    Bees 
gather  large  quantities  of  nectar  from  the  flowers.* 

2.  T.  americana*  L.     BASSWOOD,  WHITEWOOD.      A  large  tree, 
sometimes  125  ft.  high.    Leaves  larger  than  in  No.  1  (2-5  in.  wide), 
often  unsymmetrical,  heart-shaped  or  truncate  at  the  base,  sharply 
toothed.     Floral  bract  often  narrowed  at  the  base.     Fruit  somewhat 
ovoid,  £  in.  or  more  in  diameter.     Common  in  rich  woods ;  occurs 
farther  N.  than  No.  1. 

3.  T.   europsea,   L.      EUROPEAN    LINDEN.      A   good-sized   tree. 
Leaves   roundish,    obliquely   heart-shaped,    abruptly    taper-pointed, 
finely  toothed.     Flowers  differing  from  Nos.  1  and  2  in  the  absence 
of  petal-like  scales  at  the  bases  of  the  stamens.     Cultivated  from 
Europe. 

64.   MALVACEAE.     MALLOW  FAMILY. 

Herbs  or  shrubs,  with  simple,  alternate,  palmately-veined 
leaves,  with  stipules.  Flowers  regular.  Sepals  5,  often 
surrounded  by  an  involucre  at  the  base.  Petals  5.  Stamens 
numerous,  monadelphous.  Pistils  several,  more  or  less  dis- 
tinct. Fruit  a  several-celled  capsule  or  a  collection  of  1-seeded 
carpels. 


148  FOUNDATIONS  OF  BOTANY 


I.  MALVA,  L. 

Calyx  5-cleft,  with  a  small,  3-leaved  involucre.  Petals 
obcordate  or  truncate.  Styles  many,  slender,  with  stigmas 
running  down  the  sides.  Carpels  many,  1-seeded,  arranged 
in  a  circle  and  separating  from  each  other,  but  not  opening 
when  ripe. 

1.  M.  rotundifolia,  L.     COMMON  MALLOW,  CHEESES    (from  ap- 
pearance of   the  unripe  fruit).     A  common   biennial   or  perennial 
weed,  with  nearly   prostrate    stems.      Leaves   long-petioled,  round- 
kidriey-shaped,  with  crenate  margins.     Flowers  small,  whitish,  on 
long  peduncles. 

2.  M.    sylvestris,    L.     HIGH   MALLOW.     Biennial   or   perennial. 
Stem  erect,  2-3  ft.  high.      Leaves  5-7  lobed.     Flowers  purplish, 
larger  than  those  of  the  preceding  species. 

H.    ABUTILON,  Tourn. 

Calyx  5:cleft,  the  tube  often  angled.  Styles  5-20,  with 
knobbed  stigmas.  Carpels  as  many  as  the  styles,  arranged  in 
a  circle,  each  l-celled,  3-6-seeded,  and  opening  when  ripe  by 
2  valves. 

1.  A.  striatum,  Dicks.     TASSEL  TREE,  FLOWERING  MAPLE.     A 

shrub  5-10  ft.  high.  Leaves  maple-like.  Flowers  showy,  solitary, 
nodding  on  slender  peduncles.  Corolla  not  opening  widely,  orange, 
striped  with  reddish-brown  veins.  Column  of  stamens  projecting 
beyond  the  corolla  like  a  tassel.  Cultivated  in  hothouses.  From 
Brazil. 


65.   HYPERICACE^.     ST.  JOHNSWORT  FAMILY. 

Herbs,  shrubs,  or  trees.  Leaves  opposite,  often  covered 
with  translucent  or  dark  dots,  entire  or  with  glandular  teeth, 
without  stipules.  Mowers  usually  in  terminal  cymes.  Sepals 
5,  rarely  4.  Petals  as  many  as  the  sepals,  hypogynous. 
Stamens  usually  many,  more  or  less  grouped  in  bundles, 
anthers  versatile.  Pod  1-celled,  with  2-5  parietal  placentse 
and  the  same  number  of  styles,  or  else  3-7-celled,  splitting 
along  the  partitions. 


DICOTYLEDONOUS   PLANTS  149 


HYPERICUM,  L. 

Herbs,  shrubs,  or  small  trees.    Leaves  sessile,  often  dotted. 
Flowers  yellow,  perfect. 

1.  H.    perforatum,    L.      COMMON   ST.  JOHNSWORT.      Perennial. 
Stem  erect,  1-3  ft.  high,  2-ridged,  much  branched.     Leaves  linear  or 
oblong,  obtuse,  with  translucent  veins  and  dots.     Cymes  grouped  in 
corymbs,  many-flowered.     Flowers  1  in.  in  diameter.     Sepals  acute. 
Petals  much  longer  than  the  sepals,  oblique  at  the  tip  and  irregularly 
fringed.     A  common  weed  in  meadows  and  pastures  E.  and  N. 

2.  H.  nudicaule,  Walt.    ORANGE-GRASS,  PINE-WEED.    Low  (4-9  in. 
high),  slender  annual,  with  erect,  angled  or  almost  winged  wiry  stem 
and   branches.     Leaves  minute,   awl-shaped  scales.     Corolla  about 
\  in.   in  diameter,   usually  closing   by  or    before    midday.     Sandy 
banks  and  roadsides. 


66.   VIOLACE^.     VIOLET  FAMILY. 

Herbs,  with  simple,  alternate  leaves,  with  stipules.  Calyx 
of  5  persistent  sepals.  Corolla  of  5  petals,  somewhat  irreg- 
ular, one  petal  with  a  spur.  Stamens  5,  short,  the  filaments 
often  cohering  around  the  pistil  (Fig.  17).  Style  generally 
club-shaped,  with  a  one-sided  stigma,  with  an  opening  leading 
to  its  interior.  Pod  1-celled,  splitting  into  3  valves,  each 
bearing  a  placenta.  The  seeds  are  often  dispersed  by  the 
splitting  of  the  elastic  valves  (Fig.  17). 

VIOLA,  Tourn. 

Sepals  ear-like  at  the  base.  Petals  somewhat  irregular, 
some  of  them  bearded  within,  thus  affording  a  foothold  for 
bees,  the  lowest  one  with  a  spur  at  the  base.  Stamens  not 
cohering  very  much,  the  two  lowermost  with  spurs  which 
reach  down  into  the  spur  of  the  lowest  petal.  Many  species 
bear  inconspicuous  apetalous  flowers  later  than  the  showy 
ordinary  ones  and  produce  most  of  their  seed  from  these 
closed,  self-fertilized  flowers.  (See  Part  I,  Ch.  XXVIII.) 


150  FOUNDATIONS   OF   BOTANY 


§  1.  Stemless  perennials. 

1.  V.  pedata,  L.     BIRD-FOOT  VIOLET,  HORSESHOE  VIOLET,  SAND 
VIOLET.     Rootstock  stout,  upright,  not  scaly.     Leaves  all  palmately 
5-9-parted  into  linear  or  linear-lanceolate  divisions.     Flowers  showy, 
about  1  in.  broad,  pale  violet  to  whitish ;  petals  not  bearded. 

2.  V.  palmata,  L.     COMMON  BLUE  VIOLET.     Rootstock  stout' and 
scaly.     Earlier  leaves  roundish  heart-shaped  or  kidney-form  and  cre- 
nate,  with  the  sides  rolled  in  at  the  base  when  young.     The  later 
ones  variously  cleft  or  parted.     Flowers  dark  or  light  blue,  some- 
times whitish;  the  lateral  petals  bearded. 

Variety  cucullata,  Gray.  COMMON  BLUE  VIOLET,  HOOD-LEAF 
VIOLET.  Later  leaves  remaining  nearly  crenate,  like  the  earlier 
ones,  in  rich  soil  becoming  very  luxuriant. 

3.  V.  sagittata,  Ait.     ARROW-LEAVED  VIOLET,  SPADE-LEAF  VIO- 
LET.    Leaves  very  variable,  ranging  in  shape   from    oblong-heart- 


A 

FIG.  17.  —  Viola  tricolor. 
A,  stamens  and  pistil ;  S,  pistil  with  stamens  removed  ;  C,  pod  split  open. 

shaped  to  triangular-halberd-shaped,  very  often  with  an  arrow- 
shaped  base,  the  earlier  ones  on  short,  margined  petioles,  the  later 
frequently  long-petioled.  Flowers  rather  large,  otherwise  much  as 
in  the  preceding  species.  Variable  and  perhaps  an  aggregate  of 
several  distinct  species. 

4.  V.  blanda,  Willd.  SWEET  WHITE  VIOLET.  Rootstock  long, 
slender,  and  creeping.  Leaves  roundish  heart-shaped  or  kidney- 
shaped.  Flowers  rather  small,  whitish,  sweet-scented,  generally 
beardless,  with  the  lowermost  petal  exquisitely  veined  with  dark 
purple  lines.  In  damp  or  marshy  ground. 


DICOTYLEDONOUS  PLANTS  151 


§  2.  Leafy-stemmed  perennials. 

5.  V.  pubescens,   Ait.     DOWNY  YELLOW  VIOLET.     Soft,  downy, 
6-12  in.  high.     Leaves  broadly  heart-shaped,  toothed,  with   large 
stipules.     Flowers  yellow,  with  a  short  spur. 

6.  V.  canadensis,  L.    CANADA  VIOLET.    Stems  very  leafy,  smooth, 
1  ft.  or  more  high.      Leaves  heart-shaped,    taper-pointed,    serrate. 
Flowers  large  and  handsome ;  petals  white,  or  nearly  so,  inside,  the 
upper  ones  usually  violet-tinged  beneath,  lateral  petals  bearded. 

§  3.    Leafy-stemmed,  from    an  annual,  biennial,  or  occasionally  short- 
lived perennial  root:  stipules  about  as  large  as  the  leaves. 

7.  V.    tricolor,   L.      PANSY,    HEART'S-EASE..     Stem    branching, 
angular,  hardly  erect.     Leaves  variable,  more  or  less  ovate,  crenate. 
Flowers  large  (often  more  than  1  in.  across),  flattish,  short-spurred, 
exceedingly  variable  in  color.     Cultivated  from  Europe. 

Variety  arvensis.  JOHNNY-JUMP-UP,  LADY'S-DELIGHT.  A  small 
flowered  variety.  Introduced  in  gardens  and  sometimes  appearing 
like  a  native  plant. 


67.   PASSIFLORACEJE.     PASSION-FLOWER  FAMILY. 

Shrubs  or  herbs,  climbing  by  axillary  tendrils.  Leaves 
alternate,  simple,  mostly  3-lobed.  Flowers  axillary,  on  jointed 
peduncles,  solitary  or  few  together,  perfect,  regular,  often 
showy.  Calyx-tube  4-5-lobed,  persistent.  Petals  usually  5, 
inserted  on  the  throat  of  the  calyx-tube,  which  is  fringed 
with  a  crown  of  1-3  rows  of  long  and  slender  filaments. 
Stamens  5,  their  filaments  united,  and  enclosing  the  stalk  of 
the  ovary.  Styles  1-5 ;  ovary  with  3-5  parietal  placentae. 
Seeds  numerous,  fruit  fleshy. 

PASSIFLORA. 

Characters  of  the  family. 

1.  P.  incarnata,  L.  PASSION-FLOWER.  Perennial.  Stem  often 
20-30  ft.  long,  somewhat  angled  or  striate,  smooth  below,  downy 
above.  Leaves  broadly  heart-shaped,  palmately  3-5-lobed,  the  lobes 
acute,  finely  serrate,  usually  heart-shaped  at  the  base ;  petiole  bearing 


152  FOUNDATIONS   OF   BOTANY 

2  oval  glands  near  its  summit.  Flowers  2-3  in.  wide,  solitary; 
peduncles  3-bracted,  longer  than  the  petioles;  calyx-lobes  with  a 
small  horn-like  appendage  on  the  back  near  the  apex,  white  within. 
Petals  and  crown  purple  and  white.  Fruit  yellow,  about  the  size 
and  shape  of  a  hen's  egg,  edible.  Seeds  with  a  pulpy  aril.  Com- 
mon along  fence-rows  and  embankments  S.* 

2.  P.  lutea,  L.  YELLOW  PASSION-FLOWER.  Perennial.  Stem 
slender,  smooth,  6-10  ft.  long.  Leaves  broadly  heart-shaped,  3-lobed 
at  the  summit,  entire,  often  mucronate  ;  stipules  small  ;  petioles 
without  glands.  Peduncles  longer  than  the  leaves,  usually  in  pairs. 
Flowers  greenish-yellow,  £-f  in.  wide.  Fruit  purple,  oval,  \  in. 
long.  Woods  and  thickets  S.* 

68.    BEGONIACEJE.     BEGONIA  FAMILY. 

Chiefly  perennial  herbs  or  low  shrubs,  with  fleshy  or  very 
juicy  stems.  Leaves  alternate,  generally  heart-shaped  at  the 
base,  often  very  un symmetrical;  stipules  deciduous.  Flowers 
monoecious,  in  cyrnes  or  other  clusters,  on  axillary  peduncles. 
Stamens  many  (Fig.  18).  Pistillate  flowers  with  the  floral 
envelopes  borne  on  the  ovary  ;  ovary  3-angled  or  3-winged 
(Fig.  18),  very  many-seeded. 

BEGONIA,  L. 

Flowers  with  the  calyx  and  corolla  of  the  same  color, 
staminate  and  pistillate  ones  both  occurring  in  the  same  clus- 
ter. Sepals  usually  2.  Petals  2  or  in  the  fertile  flowers  3  or 
4,  sometimes  wanting.  Stamens  many  in  a  cluster,  with  short 
filaments.  Styles  of  the  fertile  flowers  3,  often  with  long, 
twisted  stigmas  (Fig.  18,  (7).  The  genus  contains  a  great  num- 
ber of  species  and  varieties,  cultivated  from  tropical  or  sub- 
tropical regions,  of  which  only  a  few  of  the  commonest  are 
here  described. 

1.  B.  Rex,  Putz.  Herb,  stemless  or  nearly  so,  from  a  fleshy  root- 
stock.  Leaves  large,  taper-pointed,  very  unequally  heart-shaped,  the 
margin  sinuous,  often  bristly  fringed,  upper  surface  wholly  silvery  or 
mottled  silvery  and  dark  green,  lower  surface  green  or  reddish  or  of 
both  colors.  Flowers  few,  large  (1^  to  If  in.  in  diameter),  varying 
from  yellow  to  pinkish.  Cultivated  from  the  Himalayas  ;  many 
varieties. 


DICOTYLEDONOUS   PLANTS 


153 


2.  B.  manicata,  Cels.     Herb,  with  a  short  and  fleshy  stem.    Leaves 
very    unevenly    heart-shaped,    taper-pointed,    the    margins   bristly 
fringed  and  sometimes  with  very  remote  teeth,  upper  surface  dark 
green,  lower  surface  and  petioles  partly  covered  with  long  fringed 
scales,  stipules  larger  and  fringed.     Flowers  flesh-colored,  handsome, 
in  a  loose  panicle  borne  on  a  long  peduncle.    Cultivated  from  Mexico. 

3.  B.  coccinea,  Hook.      Tall,  3-10  ft.  high,  somewhat  shrubby, 
often  with  many  erect,  smooth  stems  from  the  same  root.     Leaves 


CD  B 

FIG.  18.  — Begonia  Flowers. 

A,  staminate  flower ;    B,  pistillate  flower  ;   C,  twisted  stigmas,  enlarged ;  D, 
cross-section  of  ovary  ;  o,  ovary  ;  s,  sepals  ;  p,  petals. 

broadly  and  unevenly  lanceolate  or  ovate-lanceolate,  half -heart-shaped 
or  broadly  one-eared  at  the  base,  acute,  nearly  or  quite  entire,  smooth, 
dull  green  above,  sometimes  tinged  with  reddish  below.  Peduncles 
several-many-flowered,  reddish,  slender,  somewhat  nodding.  Flowers 
showy,  medium  sized,  scarlet.  Fruit  showy,  scarlet,  very  broadly 
winged.  Cultivated  from  Peru.  [Often  called  B.  rubra.~\ 

4.  B.  incarnata,  Link  and  Otto.     Herbaceous  or  mainly  so,  rather 
tall  (2-4  ft.),  stems  clustered,  slightly  reclining,  hairy  when  young, 


154  FOUNDATIONS   OF  BOTANY 

at  length  smoother.  Leaves  broadly  and  very  unequally  ovate- 
lanceolate,  tapering  toward  the  tip  but  at  the  extremity  somewhat 
blunt,  half-heart-shaped  at  the  base,  somewhat  lobed  and  sinuate- 
toothed,  rough-hairy  above  and  below  and  on  the  petioles,  dark 
green  above  with  coppery  streaks  along  the  veins.  Flowers  on 
short  peduncles,  few,  of  medium  size,  beautiful  rose-pink  in  the  bud, 
becoming  almost  white,  thickly  covered  outside  with  soft,  moss-like 
hairs.  Cultivated  from  Mexico.  [Often  called  B.  metaUica.~\ 

5.  B.  semperflorens,  Link  and  Otto.  Stems  smooth,  herbaceous, 
rather  fleshy,  branching  near  the  ground  and  reclining.  Leaves 
obtuse  or  nearly  so,  broadly  ovate,  somewhat  unevenly  heart-shaped 
or  tapering  at  the  base,  irregularly  serrate,  or  scalloped  and  wavy, 
smooth,  dark  green,  and  very  glossy  above ;  stipules  rather  large, 
nearly  ovate.  Flowers  in  small,  axillary  clusters  near  the  top  of  the 
stem,  whitish  to  crimson,  about  \\  in.  in  diameter.  Ovary  in  fruit 
very  broadly  winged.  An  easily  grown  but  homely  species.  Culti- 
vated from  S.  Brazil. 


69.   CACTACE^E.     CACTUS  FAMILY. 

Plants  usually  with  very  fleshy  and  much  thickened,  often 
globular  or  cylindrical  stems  (Fig.  49).  Leaves  usually 
wanting.  Flowers  sessile,  solitary,  often  very  showy.  Peri- 
anth consisting  of  several  rows  of  sepals  and  petals,  adnate 
below  to  the  ovary.  Stamens  many,  with  slender  filaments, 
borne  on  the  inside  of  the  perianth-tube.  Style  1  ;  stigmas 
numerous  ;  ovary  1-celled,  many-ovuled.  Fruit  a  many- 
seeded  berry. 

I.     OPUNTIA,  Tourn. 

Stem  composed  of  a  series  of  flattened  joints,  which  are 
usually  leafless  when  full  grown.  Leaves  very  small,  awl- 
shaped,  spirally  arranged,  appearing  on  the  young  joints,  but 
soon  dropping  off,  with  barbed  bristles  and  sometimes  spines 
in  their  axils.  Flowers  yellow.  Sepals  and  petals  not  much 
united  into  a  tube.  Fruit  often  eatable. 

1.  0.  vulgaris,  Mill.  COMMON  PRICKLY  PEAR.  Prostrate  or 
nearly  so,  pale  green.  Leaves  about  i  in.  long,  rather  scale-like  ; 
bristles  many,  with  few  or  no  spines.  Flowers  2  in.  or  more  in 
diameter,  with  about  8  petals.  Fruit  about  1  in.  long,  crimson 


DICOTYLEDONOUS  PLANTS  155 

when  ripe,  eatable.     Dry  rocks  and  sandy  ground,  from  Massachu- 
setts south  along  the  coast. 

2.  0.  Rafinesquii,  Engelm.    Prostrate,  green.    Leaves  £-£  in.  long, 
awl-shaped,  spreading ;  bristles  often  intermixed  with  a  few  small 
spines  and  a  larger  one  f-1  in.  long.     Flowers  larger  than  in  No.  1 
and  with  10-12  petals.     Fruit  about  1|  in.  long,  much  tapered  at 
the  base.     In  poor  soil. 

3.  0.  missouriensis,  DC.      Prostrate,  light    green.       Leaves  very 
small,  with  bristles  and  5-10  spines  in  their  axils.     Flowers  2-3  in. 
in  diameter.     Fruit  dry  and  spiny.     Wisconsin,  S.  and  W. 

I 
II.     PHYLLOCACTUS. 

Stems  cylindrical  when  old,  with  long,  flattened,  fleshy  but 
leaf-like,  sinuate  or  serrate  branches.  Flowers  nearly  or  quite 
regular,  from  the  notches  in  the  margins  of  the  joints. 

1.  P.  Ackermanni,  L.  Flowers  very  showy,  bright  red.  Perianth- 
tube  shorter  than  the  petals.  Sepals  scattered,  small  and  bract-like. 
Petals  many,  2-3  in.  long,  widely  spreading,  somewhat  channeled, 
sharp-pointed.  Cultivated  from  Mexico. 

III.    CEREUS,  DC. 

Stem  more  or  less  prismatic  but  strongly  ridged,  with  bun- 
dles of  spines  borne  on  the  ridges,  sometimes  prostrate  or 
trailing,  sometimes  erect,  columnar,  and  50  or  60  ft.  high. 
Flowers  usually  showy,  borne  on  the  sides  of  the  stem,  gener- 
ally with  a  rather  long  perianth-tube,  which  is  covered  outside 
with  scale-like  sepals,  usually  with  tufts  of  wool  in  their  axils. 
Petals  many,  mostly  long  and  spreading. 

1.  C.  speciocissimus,  DC.     Stems  2-3  ft.  high,  with  3-4  broad- 
winged  and  sinuate  ridges.     Flowers  open  in  the  daytime  and  lasting 
several  days,  red  or  crimson,  very  showy.     Petals  longer  than  the 
tube,  stamens  white,  drooping,  very  numerous.      Commonly  culti- 
vated from  Mexico. 

2.  C.  grandiflorus,  Mill.     NIGHT-BLOOMING  CEREUS.    Stems  long, 
climbing  by  aerial  roots,  nearly  cylindrical,  but  with  5  or  more  blunt 
angles.     Flowers  very  showy,  opening  only  for  one  night,  wilting 
early  in  the  morning,  extremely  fragrant.    Sepals  dull  yellow.    Petals 
pearly  white,  spreading,  6-8  in.  long.     Cultivated  from  Mexico. 


156  FOUNDATIONS   OF  BOTANY 


70.   (ENOTHERACE^.     EVENING  PRIMROSE  FAMILY. 

Herbs,  rarely  shrubs  or  trees.  Leaves  opposite  or  alternate, 
without  stipules.  Flowers  regular.  Calyx-tube  adnate  to 
the  ovary,  its  margin  2-4-lobed.  Petals  2-4,  rarely  wanting, 
perigynous,  quickly  falling  off.  Stamens  1-8.  Ovary  usually 
4-celled ;  style  thread-like  ;  stigma  entire  or  4-lobed  ;  ovules 
1  or  more  in  the  inner  angle  of  each  cell.  Fruit  a  capsule, 
berry,  or  stone-fruit.  Seeds  1  or  more,  smooth  or  hairy. 


I.     (ENOTHERA,  L. 

Herbs,  rarely  shrubby.  Leaves  alternate.  Flowers  large, 
yellow,  red,  or  purple.  Calyx-tube  4-angled.  Petals  4. 
Stamens  8.  Capsule  usually  4-celled,  many-seeded. 

1.  (E.  fruticosa,  L.      SUNDROPS.      Biennial  or  perennial.      Stem 
erect,  often  rather  stout,  1-3  ft.  high,  downy  or  sometimes  smooth. 
Leaves  lance-oblong,  or  in  one  variety  linear  or  nearly  so,  usually 
minutely   toothed.      Racemes   often    corymbed.      Flowers   open  in 
the  daytime,  showy,  yellow,  1-2  in.  in  diameter.     Pod  nearly  sessile, 
ellipsoidal,  with  prominent  ribs  and  strong  wings.    Dry  soil,  common. 

2.  (E.  pumila,  L.     SMALL  SUNDROPS.     Much  like  the  preceding, 
but  smaller.    Leaves  oblanceolate  or  oblong,  entire.    Flowers  £-1  in. 
in  diameter.     Pod  club-shaped.     In  dry  soil. 


H.    FUCHSIA,  L. 

Herbs,  shrubs,  or  trees.  Leaves  opposite  or  3  in  a  whorl. 
Flowers  showy.  Calyx  colored,  tubular-funnel-shaped,  the 
tube  extending  much  beyond  the  ovary,  the  margin  4-lobed. 
Petals  4,  borne  in  the  throat  of  the  calyx.  Stamens  8,  pro- 
jecting outside  the  corolla.  Capsule  berry-like,  ellipsoidal, 
4-angled. 

1.  F.  macrostemma,  Ruiz  and  Pav.  COMMON  FUCHSIA,  LADIES' 
EARDROP.  Smooth.  Leaves  slender-petioled,  toothed.  Flowers  on 
long,  drooping  peduncles  from  the  axils  of  the  leaves.  Calyx-tube 
oblong  or  a  short  cylinder,  not  as  long  as  its  spreading  lobes.  Petals 
obovate  and  notched,  wrapped  spirally  around  the  projecting  fila- 


DICOTYLEDONOUS   PLANTS  157 

ments  and  style.  Found  in  many  varieties,  sometimes  the  calyx 
white  or  nearly  so  and  the  petals  dark  or  with  dark  calyx  and  light 
petals.  Cultivated  from  Chili. 

m.    CIRCJEA,  Tourn. 

Slender,  erect  herbs,  with  creeping  rootstocks.  Stem  simple. 
Leaves  opposite,  petioled.  Flowers  small,  in  terminal  and 
lateral  racemes.  Calyx-tube  ovoid,  the  limb  2-parted,  reflexed, 
deciduous.  Petals  2,  inversely  heart-shaped,  inserted  with  the 
2  stamens  under  a  margin  of  a  disk  which  is  borne  on  the 
pistil.  Ovary  1-2-celled  ;  style  thread-like  ;  stigma  knobbed, 
2-lobed  ovules,  1  in  each  cell.  Fruit  ovoid,  not  splitting  open, 
covered  with  hooked  bristles. 

1.  C.  lutetiana,  L.  ENCHANTER'S  NIGHTSHADE.  Stem  1-2  ft. 
high,  glandular-downy.  Leaves  ovate,  faintly  toothed,  long-petioled. 
Flowers  i  in.  in  diameter,  white  or  pink,  on  slender  pedicels,  jointed 
at  the  base.  Damp,  shaded  places ;  very  common. 


71.   ARALIACE^.     GINSENG  FAMILY. 

Herbs,  shrubs,  or  trees.  Leaves  alternate,  simple  or  com- 
pound ;  stipules  adnate  to  the  petiole  or  wanting.  Flowers 
regular,  in  umbels  or  heads.  Limb  of  the  calyx  borne  on 
top  of  the  ovary,  very  short.  Petals  5,  very  deciduous. 
Stamens  5,  filaments  bent  inward,  anthers  versatile.  Ovary 
2-celled  or  several-celled  ;  styles  or  stigmas  as  many  as  the 
cells  ;  ovule  1  in  each  cell.  Fruit  a  stone-fruit  or  berry. 
[The  English  ivy,  an  important  member  of  the  family,  flowers 
too  late  for  school  study.] 

ARALIA,  Tourn. 

Perennial  plants  with  pungent  or  spicy  roots,  bark,  and  fruit. 
Leaves  once  or  more  compound.  Flowers  more  or  less  monoe- 
cious, white  or  greenish,  in  umbels.  Stone-fruit,  berry-like. 

1.  A.  hispida,  Vent.  BRISTLY  SARSAPARILLA,  WILD  ELDER. 
Stem  1-2  ft.  high,  rather  shrubby  below,  with  prickly  bristles. 
Leaves  once  or  twice  pinnate ;  leaflets  ovate,  acute,  cut-serrate  and 


158  FOUNDATIONS   OF   BOTANY 

often  lobed.  Peduncle  bearing  several  umbels  of  cream-colored 
flowers,  in  a  terminal  corymb.  Fruit  blue-black.  Dry  fields  and 
pastures  E. 

2.  A.  nudicaulis,  L.  SARSAPARILLA.  Perennial  herb  ;  roots  very 
long,  somewhat  fleshy,  aromatic;  stem  very  short  or  none.  Leaf 
solitary,  from  a  sheathing  base,  petioled,  6-12  in.  long  ;  compound  in 
threes,  each  division  3-5-pinnate ;  leaflets  oval  or  ovate,  taper-pointed, 
finely  and  sharply  serrate,  smooth  above,  often  downy  below.  Scape 
nearly  as  long  as  the  petiole,  usually  bearing  3  short,  peduncled 
umbels.  Flowers  greenish.  Styles  distinct.  Fruit  globose,  black. 
In  rich  woods. 


72.    UMBELLIFER^.     PARSLEY  FAMILY. 

Herbs,  usually  with  hollow,  grooved  stems.  Flowers  small, 
generally  in  umbels.  Calyx-tube  adnate  to  the  ovary  ;  limb 
of  the  calyx  either  wanting  or  present  only  as  a  5-toothed  rim 
or  margin  around  the  top  of  the  ovary.  Petals  5.  Stamens  5, 
inserted  on  the  disk,  which  is  borne  by  the  ovary  (Fig.  19). 
Ovary  2-celled  and  2-ovuled  (Fig.  19),  ripening  into  2 
akene-like  carpels,  which  separate  from  each  other.  Each 
carpel  bears  5  longitudinal  ribs,  in  the  furrows  between  which 
secondary  ribs  frequently  occur.  On  a  cross-section  of  the 
fruit,  oil-tubes  are  seen,  traversing  the  interspaces  between 
the  ribs,  and  near  the  surface  of  the  fruit  (Fig.  19).  The 
seeds  contain  a  small  embryo,  enclosed  in  considerable  endo- 
sperm. [The  family  is  a  difficult  one,  since  the  flowers  are 
so  much  alike  that  the  species  are  distinguished  from  each 
other  mainly  by  minute  characteristics  of  the  fruit.] 

I.    ERYNGIUM,  Tourn. 

Annual,  biennial,  or  perennial  herbs.  Stems  erect  or  creep- 
ing. Leaves  simple,  mostly  linear  and  spiny-toothed.  Flowers 
white  or  blue,  in  dense,  bracted  heads  or  spikes,  flowers  brac- 
teolate.  Calyx-teeth  rigid,  persistent.  Petals  erect,  pointed. 
Styles  slender.  Fruit  top-shaped,  scaly  or  granular,  ribs  want- 
ing, oil-tubes  usually  5,  minute.* 


DICOTYLEDONOUS   PLANTS  159 

1.  E.  yuccaefolium,  Michx.  BUTTON  SNAKEROOT,  RATTLESNAKE 
MASTER.  Perennial.  Stem  erect,  branched  above,  striate,  covered 
with  a  bloom,  2-3  ft.  high.  Leaves  linear,  often  2  ft.  or  more  in 
length,  rigid,  covered  with  a  bloom,  parallel-veined,  fringed  with  white 
bristles.  Bracts  shorter  than  the  heads,  entire,  bracteoles  similar 
but  smaller.  Flowers  white.  Fruit  scaly.  In  damp  soil.* 

II.    SANICULA,  Tourn. 

Slender,  erect,  perennial  herbs.  Eootstock  short,  stout, 
creeping.  Leaves  palmately  cut.  Umbels  small,  somewhat 
globular,  irregularly  compound  ;  bracts  leafy  ;  bracteoles  few ; 


o-  '  W    A  C  TT   B 


FIG.  19.  —  Flower  and  Fruit  of  Umbelliferse. 

A,  flower  of  Fceniculum;  JS,  fruit  of  Heracleum  ;  (7,  fruit  of  Heracleum,  cross-sec- 
tion ;  o  (in  A),  ovary  ;  d,  disk  ;  s</,  stigma  ;  s,  stamens  ;  o  (in  J3,  and  C),  oil-tubes  ; 
r,  ribs.  A,  B,  and  C  all  enlarged. 

flowers  perfect  or  staminate,  greenish,  or  yellowish.  Calyx- 
teeth  as  long  as  the  small  petals,  sharp-pointed.  Fruit  ovoid, 
covered  with  hooked  prickles,  ribless,  each  carpel  with  5  oil- 
tubes. 

1.  S.  marylandica,  L.  SANICLE,  BLACK  SNAKEROOT.  Stem  rather 
stout,  1^-4  ft.  high.  Leaves  3-7 -parted,  the  divisions  irregularly 
serrate  or  dentate  and  often  cut.  Petals  greenish-white,  very  small. 
Fruit  with  two  slender,  recurved  styles  at  the  apex.  Rich  woods. 

III.    ERIGENIA,  Nutt. 

A  little  smooth  plant  with  a  slender,  unbranched  stem,  from 
a  deep,  nearly  globular  tuber.  Leaves  1  or  2,  twice  or  thrice 
compound  in  threes.  Flowers  few,  small,  in  an  imperfect 
leafy-bracted  umbel.  Calyx-teeth  wanting.  Petals  obovate 


160  FOUNDATIONS   OF   BOTANY 

or  spatulate.  Fruit  smooth,  roundish,  notched  at  both  ends, 
the  two  carpels  touching  only  at  top  and  bottom,  each  with 
5  slender  ribs. 

1.  E.  bulbosa,  Nutt.  HARBINGER  OF  SPRING,  TURKEY  PEA, 
PEPPER-AND-SALT.  Stem  scape-like,  with  a  leaf  which  forms  an 
involucre  to  the  flower-cluster.  Petals  white,  anthers  brown-purple. 
A  pretty,  though  inconspicuous  plant ;  welcomed  as  one  of  the  earliest 
spring  flowers  S. 

IV.     OSMORRHIZA,  Raf. 

Perennials,  springing  from  stout,  aromatic  roots.  Leaves 
compound  in  threes.  Flowers  white,  in  compound  umbels. 
Calyx-teeth  wanting.  Fruit  linear  or  nearly  so,  tapering  at 
the  base,  with  5  equal  bristly  ribs,  without  oil-tubes. 

1.  0.  brevistylis,  DC.       HAIRY   SWEET   CICELY.     Rather  stout 
and  hairy,  especially  when  young,  1^-3  ft.  high.     Lower  leaves  on 
long  petioles,  large,  twice  compound  in  threes,  the  divisions  ovate  or 
oval,  cut-toothed,  upper  leaves  nearly  sessile,  less  compound.    Umbels 
with  long  peduncles  and  spreading  rays.     Style  and  its  enlarged 
base  somewhat  conical.     Root  nauseous.     Rich  woods. 

2.  0.  longistylis,  DC.     SMOOTH-LEAVED  SWEET  CICELY.    Much 
like  No.  1  in    general  appearance.      Smooth  or   nearly  so.     Style 
rather  thread-like.     Root  of  a  pleasant  aromatic  flavor  (as  is  also 
the  fruit).     Woods. 

Caution.  So  many  plants  of  this  family  have  actively  poisonous 
roots  and  foliage  that  it  is  unsafe  for  any  one  but  a  botanist,  who 
can  distinguish  the  poisonous  species  from  the  harmless  ones,  to 
taste  them. 

V.    CARUM,  L. 

Herbs,  with  slender,  smooth  stems.  Leaves  pinnately  com- 
pound, smooth.  Umbels  compound.  Flowers  white  or  yel- 
lowish. Calyx-teeth  minute.  Fruit  smooth,  oblong  or  ovate, 
with  thread-like  ribs  ;  oil-tube  single  in  the  intervals  between 
the  ribs  ;  base  of  the  styles  thickened  into  a  conical  mass. 

1.  C.  Carui,  L.  CARAWAY.  Perennial.  Leaves  large,  with  the  leaf- 
lets cut  into  numerous  thread-like  divisions.  Flowers  white.  Fruit 
aromatic,  used  somewhat  in  this  country  and  more  in  N".  Europe  for 
flavoring  cookies,  bread,  etc.  Introduced  from  Europe. 


DICOTYLEDONOUS   PLANTS  161 


VI.     THASPIUM,  Nutt. 

Perennial  herbs.  Stem  erect.  Leaves  1-2,  compound  in 
threes.  Umbels  compound,  involucre  and  involucels  usually 
wanting.  Flowers  yellow  or  purple.  Calyx-teeth  small, 
acute.  Fruit  ovoid  or  oblong,  somewhat  laterally  compressed ; 
carpels  smooth,  strongly  ribbed,  oil-tubes  between  the  ribs.* 

1.  T.  barbinode,  Nutt.  HAIRY  MEADOW  PARSNIP.  Stem  erect, 
branching  above,  downy  at  the  nodes,  2-7  ft.  high.  Leaves  petioled, 
slightly  downy,  leaflets  mostly  thin,  ovate,  toothed,  incised  or  lobed 
toward  the  apex,  entire  toward  the  base.  Umbels  long-peduncled, 
few-rayed.  Fruit  oblong,  lateral  and  central  ribs  strongly  winged. 
Along  streams.* 

VII.    ZIZIA,  Koch. 

Smooth  perennials.  Leaves  generally  as  in  Thaspium. 
Involucre  wanting  ;  involucels  of  small  bractlets.  Umbels 
compound.  Flowers  yellow.  Calyx-teeth  prominent.  Fruit 
more  or  less  ovoid,  smooth,  with  thread-like  ribs,  oil-tubes 
large  and  solitary  between  the  ribs  and  a  little  one  in  each 
rib  ;  the  central  fruit  of  each  umbellet  sessile. 

1.  Z.  aurea,  Koch.     MEADOW   PARSNIP,  GOLDEN  ALEXANDERS. 

Smooth,  stem  erect,  1-2  ft.  high.  Root-leaves  mostly  heart-shaped 
and  serrate,  stem-leaves  usually  once  compound  in  threes.  Flowers 
deep  yellow.  Fruit  between  globose  and  ovoid,  about  £  in.  long,  all 
the  ribs  generally  winged.  Woods  and  thickets. 

VIH.    PASTINACA,  L. 

A  tall,  smooth  biennial  with  a  stout,  grooved  stem.  Leaves 
pinnate.  Flowers  yellow,  in  large  umbels,  with  hardly  any 
involucre.  Calyx-teeth  wanting.  Fruit  oval,  very  flat,  with 
a  thin  wing,  oil-tubes  single,  running  the  whole  length. 

1.  P.  sativa,  L.  COMMON  PARSNIP.  Cultivated  from  Europe 
for  its  large,  conical,  sweet,  and  edible  roots.  Also  introduced  in 
waste  places. 

IX.    HERACLEUM,  L. 

A  stout  perennial,  with  the  very  large  leaves  compound  in 
threes.  Umbels  large,  compound,  with  the  involucels  many- 


162  FOUNDATIONS   OF  BOTANY 

leaved.  Petals  white,  inversely  heart-shaped,  the  outer  ones 
usually  2-cleft  and  larger.  Calyx  with  5  small  teeth.  Fruit 
tipped  with  a  thick,  conical  enlargement  of  the  style,  with 
three  blunt  ribs  on  the  outer  surface  of  each  carpel  and  a 
large  oil-tube  in  each  interval  between  the  ribs.  Seeds  flat. 

1.  H.  lanatum,  Michx.  Cow  PARSNIP.  Stem  grooved  and  woolly, 
4-8  ft.  high.  Leaflets  petioled,  broad,  deeply  and  irregularly  toothed. 

X.    DAUCUS,  L 

Annual  or  biennial,  bristly-hairy  herbs.  Leaves  pinnately 
twice  or  more  compound,  the  divisions  slender.  Umbels  com- 
pound, many-rayed.  Flowers  small,  white.  Calyx-teeth  slen- 
der or  wanting.  Petals  notched,  the  point  bent  inward,  often 
unequal.  Fruit  ovoid  or  ellipsoid,  with  rows  of  spines. 

1.  D.  Carota,  L.  COMMON  CARROT.  Erect,  1-3  ft.  high,  \vith  a 
conical,  fleshy,  orange-colored  root.  Lower  and  root-leaves  2-3 
pinnate.  Central  flower  of  each  umbel  and  sometimes  of  each 
umbellet  larger  and  very  dark  purple,  with  the  corolla  irregular. 
Cultivated  from  Europe  for  the  edible  roots;  also  introduced  in 
pastures  and  meadows  and  along  roadsides  E. 


73.   CORN  ACE  JE.     DOGWOOD  FAMILY. 

Shrubs  or  trees,  rarely  herbs.  Leaves  opposite  or  alter- 
nate, without  stipules.  Flowers  small,  regular,  variously 
clustered.  Calyx-tube  adnate  to  the  ovary  ;  limb  of  the  calyx 
very  short.  Petals  4-5,  borne  on  the  margin  of  a  disk  on  top 
of  the  ovary.  Stamens  4-5,  inserted  with  the  petals.  Ovary 
1-4-celled,  with  one  ovule  in  each  cell;  style  1.  Fruit  (in 
our  species)  a  1-2-celled  and  1-2-seeded  stone-fruit. 

I.    CORNUS,  Tourn. 

Trees,  shrubs,  or  herbs.  Leaves  usually  opposite.  Flowers 
in  forking  cymes,  or  in  umbels  or  heads,  each  with  an  invo- 
lucre, white  or  yellow.  Calyx-teeth  4.  Petals  4.  Stamens  4. 
Ovary  2-celled.  Stone-fruit,  ovoidal  or  ellipsoidal,  the  stone 
2-celled. 


DICOTYLEDONOUS   PLANTS  163 

1.  C.  canadensis,  L.     DWARF  CORNEL,  BUNCH-BERRY,  PUDDING- 
BERRY.     Stem  herbaceous,  excepting  at  the  base,  low  (3—9  in.),  and 
imbranched.    Rootstock  rather  woody,  slender,  and  creeping.    Leaves 
in.  what  appears  to  be  a  whorl  of  4  or  6  at  the  summit  of  the  stem, 
sessile,  ovate,  oval  or  nearly  so,  acute  at  each  end,  entire,  smooth  or 
very  slightly  downy.     Flower-stalk  slender,  j— 1^  in.  long,  with  a 
whorl  of  4-6  large,  white,  petal-like  bracts,  forming  an  involucre 
round  the  small  head  of  greenish  flowers  ;  the  head  with  its  invo- 
lucre appearing  to  others  than  botanists  like  a  single  flower.     Fruit 
nearly  spherical,  scarlet,  about  £  in.  in  diameter,  in  a  close  cluster, 
sweet  and  eatable,  though  rather  insipid.    Damp  woods,  especially  N". 

2.  C.    florida,   L.      FLOWERING    DOGWOOD.      Small    trees ;  bark 
rough,  black.     Leaves  opposite,  petioled,  ovate  to  ovate-lanceolate, 
entire,  green  and  shining  above,  paler  and  often  downy  beneath. 
Flowers  small,  greenish,  in  heads  which  are  subtended  by  4  large, 
white  or  pink,  inversely  heart-shaped  bracts,  thickened  and  greenish 
at  the  notch.     Fruit  ovoid,  bright  red.     In  rich  woods  S.  and  E.* 

3.  C.   circinata,  L'Her.      ROUND-LEAVED    DOGWOOD.      A   shrub 
3-10  ft.  high,  with  green,  warty  twigs.     Leaves  petioled,  roundish- 
oval,  contracted  to  an  abrupt  point,  entire,  usually  rounded  or  trun- 
cate  at  the  base,  pale  and   soft-downy  beneath.     Flowers  in  flat 
cymes,  l|-2£  in.  in  diameter.     Fruit  globose,  light  blue,  ±  in.  or  less 
in  diameter.     Thickets  often  in  rocky  soil  N.  and  along  Alleghany 
Mountains. 

4.  C.  sericea,  L.     KINNIKINNIK.     A  shrub,  6-10  ft.  high  ;  twigs 
purple,  downy  when  young.      Leaves  opposite,  petioled,   ovate  or 
oblong,  taper-pointed,  smooth  above,  silky-downy  below.     Flowers 
white,  in  rather  close  cymes.     Fruit  blue,  stone  somewhat  oblique. 
In  low  woods.* 

5.  C.  asperifolia,  Michx.     ROUGH-LEAVED  DOGWOOD.     A  shrub 
8-12  ft.  high  ;  twigs  slender,  reddish-brown,  often  warty,  densely 
downy  when   young.     Leaves   opposite,  short-petioled,   lance-ovate 
or  oblong,  acute  or  taper-pointed,  with  rough  down  above,  downy- 
woolly  below.      Cymes  flat,  spreading,  the  peduncle  and  branches 
covered  with  rough  down.     Flowers  white.      Fruit  white  or   pale 
blue,  stone  depressed-globose.     In  dry  woods.* 

6.  C.  stolonifera,  Michx.     RED  OSIER  DOGWOOD.     A  shrub  3-15 
ft.  high,  with  smooth,  reddish-purple  bark  on  all  the  younger  twigs, 
spreading  by  suckers  from  the  base  and  therefore  the  stems  usually 
clustered.     Leaves  on  rather  slender  petioles,  acute  or  taper-pointed, 
rounded  or  tapered  at  the  base,  covered  at  least  beneath  by  very  fine, 
closely  appressed  hairs.     Fruit  white  or  nearly  so,  globose,  \  in.  or 
more  in  diameter.     Common  in  wet  ground,  especially  N". 

7.  C.  alternifolia,  L.     ALTERNATE-LEAVED  DOGWOOD.     A  shrub 
or   small   tree;    twigs   greenish,  striped.     Leaves   alternate,  often 


164  FOUNDATIONS   OF   BOTANY 

clustered  at  the  ends  of  the  twigs,  long-petioled,  oval,  acute  at  the 
apex  and  often  at  the  base,  minutely  toothed,  pale  and  covered  with 
fine,  appressed  hairs  beneath  ;  cymes  loose  and  open.  Flowers  white. 
Fruit  deep  blue.  Banks  of  streams.* 

II.    NYSSA,  L. 

Trees  or  shrubs.  Leaves  alternate,  petioled,  entire  or  few- 
toothed.  Flowers  somewhat  monoacious  or  dioecious,  the 
staminate  in  many-flowered  heads  or  cymes,  the  pistillate  in 
small  clusters  or  solitary.  Calyx-tube  5-toothed  or  truncate. 
Petals  minute  or  wanting.  Stamens  5-10.  Ovary  1-celled, 
1-ovuled  ;  style  long  and  recurved.  Fruit  a  1-seeded  stone- 
fruit. 

1.  N.    sylvatica,    Marsh.      BLACK   GUM.      A   tree    with    widely 
spreading  branches  and  dark,  rough  bark,  wood  light-colored,  very 
tough,  base  of  trunk  often  enlarged.     Leaves  often  clustered  at  the 
ends  of  the  twigs,  oval  or  obovate,  taper-pointed  or  obtuse  at  the 
apex,  entire,  smooth  and  shining  above,  downy  beneath,  becoming 
bright  red  in  autumn.     Staminate  flowers  in  heads.     Pistillate  3-10 
in  a  long-peduncled  cluster.     Fruit  ovoid,  dark  blue  or  nearly  black, 
%  in.  long,  stone  slightly  ridged.     In  rich,  wet  soil  S.  and  E.* 

2.  N.  uniflora,  Wang.     TUPELO.      A   large   tree,  similar  to  the 
preceding.     Leaves  long-petioled,  oval  or  ovate,  acute  at  each  end, 
entire  or  coarsely  toothed,  the  lower  sometimes  heart-shaped,  smooth 
above,  downy  beneath,  4-8  in.  long.     Staminate  flowers  in  heads. 
Pistillate  flowers  on  long  peduncles,  solitary.    Fruit  ovoid,  dark  blue, 
stone  sharply  ridged.     In  swamps  S.  and  E.* 


74.    PYROLACEJE.     PYROLA  FAMILY. 

Perennial  herbs,  evergreen  or  else  pale  and  without  chlo- 
rophyll. Petals  usually  free  from  each  other  and  falling  off 
separately  after  flowering.  Stamens  hypogynous,  the  anthers 
without  appendages  and  opening  by  pores  or  by  a  transverse 
slit.  Fruit  a  capsule  containing  a  great  number  of  very  small 
seeds. 

L    CHIMAPHILA,  Pursh. 

Low  plants,  nearly  herbaceous,  with  reclining  stems,  from 
long,  horizontal,  underground  shoots.  Leaves  opposite  or 


DICOTYLEDONOUS  PLANTS  165 

whorled,  leathery,  shining,  evergreen,  on  short  u  petioles. 
Flowers  fragrant,  white  or  purplish,  on  a  corymb  or  umbel 
which  terminates  the  stem.  Calyx  5-cleft  or  5-parted,  per- 
sistent. Petals  5,  concave,  roundish,  spreading.  Stamens 
10,  the  filaments  enlarged  and  downy  in  the  middle,  the 
anthers  somewhat  4-celled,  opening  when  mature  by  pores  at 
the  outer  end.  Style  top-shaped,  nearly  buried  in  the  top  of 
the  globular  ovary.  Capsule  erect,  5-celled. 

1.  C.  umbellata,  Nutt.     PRINCE'S  PINE,  PIPSISSEWA.     Branches 
leafy,  4—12  in.  high.    Leaves  spatulate  or  wedge-oblanceolate,  obtuse 
or  nearly  so,  sharply  serrate,  very  green  and  glossy.     Flowers  sev- 
eral, umbelled  or  somewhat  corymbed,  white  or  pinkish,  the  anthers 
violet.     Dry  woods,  especially  under  pine  trees. 

2.  C.  maculata,  Pursh.     SPOTTED  WINTERGREEN.     Much  resem- 
bles No.  1,  but  has  only  scattered  teeth  on  the  leaves,  which  are 
mottled  with  white  on  the  upper  surface  and  are  often  broad  or 
rounded  at  the  base.     Dry  woods. 


H.    PYROLA,  Tourn. 

Biennial  or  perennial,  almost  woody  herbs  ;  rootstock  slen- 
der and  creeping.  Leaves  mostly  radical,  with  broad  petioles, 
evergreen.  Flowers  in  racemes,  nodding,  on  a  bracted  scape. 
Sepals  5.  Corolla  usually  globose,  of  5  free  or  nearly  free, 
roundish  petals.  Stamens  10,  in  pairs  opposite  the  petals, 
hypogynous  ;  anthers  as  in  Chimaphila.  Capsule  globose, 
5-celled,  splitting  into  5  valves,  the  latter  usually  with  downy 
edges. 

1.  P.  elliptica,  Nutt.     SHIN-LEAF.     Scape  5-10  in.  high.     Leaf- 
blades  obovate-oval  or  elliptical,   rather   thin,   dark  green,  faintly 
scalloped,    almost    always    longer    than    their   margined    petioles. 
Flowers  greenish-white,  very  fragrant.      Rich,  usually  dry  woods, 
especially  N. 

2.  P.  rotundifolia,  L.      ROUND-LEAVED  WINTERGREEN.      Scape 
6-20  in.  high.    Leaf-blades  roundish  or  oval,  leathery,  shining  above, 
faintly  scalloped,  often  rounded  at  the  base  or  almost  heart-shaped, 
usually  shorter  than  the  slightly  margined  petioles.    Flowers  white, 
very  fragrant.     Varies  greatly.     Usually  in  dry  woods  N. 


166  FOUNDATIONS   OF  BOTANY 


HI.    MONOTROPA,  L. 

Leafless,  simple,  erect,  white,  brown,  or  red  root-parasites 
or  saprophytes  or  fed  by  slender  fungus-threads  which  cluster 
on  the  roots.  Stem  scaly,  the  upper  scales  often  passing  into 
bracts.  Flowers  solitary  or  in  spikes  or  racemes.  Sepals  or 
bracts  2-5,  erect,  deciduous.  Petals  4  or  5,  erect  or  spreading. 
Stamens  8  or  10,  hypogynous,  the  filaments  awl-shaped,  anthers 
kidney-shaped.  Ovary  4-5-celled  ;  style  simple  ;  stigma  disk- 
like,  with  4-5  rays. 

1.  M.  uniflora,  L.     INDIAN  PIPE.     Stem  smooth,  fleshy,  4-6  in. 
high.     Bracts  ovate  or  lanceolate.     Flower  single,  tubular,  f-1  in. 
long,  inodorous.     Stamens  a  little  shorter  than  the  petals.     Capsule 
angled,  ^-f  in.  long.    Whole  plant  waxy-white,  turning  black  in  dry- 
ing.    In  moist,  shady  woods  N".  and  E.* 

2.  M.  Hypopitys,  L.    PINE-SAP.     Stems  single  or  clustered,  white 
or  reddish,  4-8  in.  high.    Bracts  ovate-lanceolate.     Flowers  several, 
in  a  scaly  raceme,  fragrant,  |—f  in.  long.      Capsule  oval,  £  in.  long. 
In  dry,  shady  woods,  especially  under  oaks  or  pines.* 


75.   ERICACE^.     HEATH  FAMILY. 

Usually  shrubs  or  slightly  shrubby  plants.  Leaves  simple, 
generally  alternate.  Corolla  commonly  regular,  4-5-cleft, 
sometimes  polypetalous.  Stamens  hypogynous,  distinct,  as 
many  or  twice  as  many  as  the  petals,  the  anthers  mostly 
opening  by  a  hole  at  the  end.  Ovary  usually  with  as  many 
cells  as  there  are  corolla-lobes  j  style  1.  Seeds  small,  with 
endosperm. 

A. 

Shrubs  or  small  trees.     Calyx  free  from  the  ovary.     Corolla  hypogynous, 
usually  gamopetalous. 

Shrubs  or  small  trees,  with  showy  flowers.     Anthers  not  held 
down  in  pockets  in  the  corolla.  Rhododendron,  I. 

Shrubs,  with  showy  flowers.     Anthers  at  first  held  in  pocket- 
like  depressions  in  the  corolla.  Kalmia,  II. 


DICOTYLEDONOUS   PLANTS  167 

Shrubs,  with  small,  mostly  white,  urn-shaped  flowers. 

Andromeda,  III. 
A  prostrate  plant,  hardly  at  all  shrubby.     Leaves  rather  large, 

often  l£  in.  wide,  and  veiny.  Epigaea,  IV. 

A  trailing  plant  with  small  (about  £  in.  wide),  thick,  evergreen 

leaves.  Arctostaphylos,  V. 

B. 

Shrubs.  Calyx-tube  adnate  to  the  ovary,  on  which  the  gamopetalous 
corolla  and  the  stamens  are  borne.  Fruit  a  true  berry  or  resembling 
one. 

Fruit  a  berry-like  stone-fruit,  with  10  nutlets  which  resemble 

seeds.  Gaylussacia,  VI. 

Fruit  a  berry  with  many  small  seeds.  Vaccinium,  VII. 

I.    RHODODENDRON,  L. 

Shrubs,  often  much,  branched.  Leaves  alternate,  thin, 
deciduous.  Flowers  very  showy,  in  terminal  umbels,  from 
scaly  buds,  which  became  well  developed  the  previous  season. 
Calyx  very  small,  5-parted.  Corolla  bell-shaped,  the  tube 
long  and  slender,  the  limb  spreading  and  somewhat  one-sided. 
Stamens  5  or  10,  declined ;  anthers  awnless.  Style  long  and 
slender,  declined ;  stigma  knobbed.  Capsule  oblong  or  linear, 
5-celled,  many-seeded ;  seeds  very  small,  scale-like. 

1.  R.  nudiflorum,  Torr.     WILD  HONEYSUCKLE,  ELECTION  PINK. 
A  branching  shrub,  4-6  ft.  high ;  twigs  smooth  or  with  a  few  coarse 
hairs.     Leaves  obovate  or  oblong,  ciliate-serrate,  downy,  becoming- 
smooth  above ;   petioles  short.     Flowers  appearing  with  or  before 
the  leaves,  pink  or  white,  sometimes  yellowish,  fragrant,  1-2   in. 
wide,  tube  downy  but  not  glandular.     Capsule  erect,  linear-oblong, 
|-|  in.  long.     Swamps  and  banks  of  streams;   flowers  extremely 
variable  in  size  and  color.* 

2.  R.   viscosum,   Torr.     SWAMP   HONEYSUCKLE,    SWAMP   PINK. 
A  shrub,  4-6  ft.  high;  branches  hairy.     Leaves  obovate,  leathery, 
mucronate  at  the  apex,  mostly  smooth  above,  downy  on  the  veins 
beneath ;    petioles  very  short.      Flowers  appearing  later  than  the 
leaves,  white,  fragrant,  1^-2  in.  long;  tube  long,  glandular-viscid; 
capsule  erect,  ^-|  in.  long,  bristly.     In  swamps.* 


168  FOUNDATIONS   OF  BOTANY 


II.    KALMIA,  L. 

Erect  and  branching  shrubs.  Leaves  alternate,  opposite 
or  in  threes,  entire,  leathery,  evergreen.  Flowers  showy,  in 
corymbs  or  1-3  in  the  axils.  Calyx  5-parted.  Corolla  flat- 
bell-shaped  or  wheel-shaped,  5-lobed.  Stamens  10,  the  anthers 
placed  in  pouches  in  the  corolla,  filaments  straightening  elas- 
tically  at  maturity  and  so  bringing  the  anthers  in  contact  with 
any  large  insect-visitor.  Style  long  and  slender.  Capsule 
globose,  5-celled,  many-seeded. 

1.  K.  angustifolia,  L.     SHEEP  LAUREL.     A  shrub,  1-3  ft.  high, 
with  smooth,  nearly  erect  branches.     Leaves  petioled,  opposite  or  in 
threes,  oblong,  obtuse  at  both  ends,  dark  green  above,  paler  beneath. 
Corymbs  lateral,   glandular.     Flowers  purple   or  crimson,  |— ^  in 
broad ;  pedicels  slender,  recurved  in  fruit.     Calyx  downy,  persistent. 
Style  persistent ;  capsule  depressed-globose.    On  hillsides  ;  abundant 
northward.* 

2.  K.  latifolia,  L.    CALICO  BUSH,  MOUNTAIN  LAUREL.     A  shrub, 
4-10  ft.  high.     Branches  stout,  smooth.     Leaves  mostly  alternate, 
petioled,  elliptical  or  oval,  acute  at  each  end,  smooth  and  green  on 
both  sides.     Corymbs  terminal,  compound.     Flowers  white  to  rose- 
color,  showy,  1  in.  broad.   Calyx  and  corolla  glandular;  pedicels  long, 
slender,  sticky-glandular,  erect  in  fruit ;  calyx  and  style  persistent. 
Shady  banks  on  rocky  or  sandy  soil.* 


IE.    ANDROMEDA,  L. 

A  small  shrub,  with  scaly  buds.  Leaves  alternate. 
Flowers  in  nearly  terminal  umbels,  white  or  pink.  Sepals  4. 
Corolla  hypogynous,  globose,  with  a  5-cleft,  reflexed  limb. 
Stamens  10,  hypogynous,  not  projecting  beyond  the  corolla; 
filaments  bearded.  Ovary  5-celled;  style  simple;  stigma 
obtuse  or  enlarged.  Capsule  somewhat  globose,  5-valved. 
Seeds  small,  smooth  and  hard. 

1.  A.  polifolia,  L..    WILD  ROSEMARY.     Stems  long,  rooting  at 
the  base,  with  somewhat  erect,  twiggy,  smooth  branches,  6-18  in. 
high.     Leaves  elliptical-lanceolate,  smooth  and  shining,  thick  and 
evergreen.     Flowers  small,  purplish.     Wet  bogs,  common  N". 

2.  A.  Mariana,  L.     STAGGER-BUSH.    Usually  smooth,  2-4  ft.  high. 
Leaves  moderately  thin  and  deciduous,  oblong  or  oval,  1-3  in.  long. 
Flowers  rather  small,  white  or  pinkish,  nodding,  in  racemes  on  the 


DICOTYLEDONOUS   PLANTS  169 

naked  shoots  of  the  preceding  year.     Low  grounds.     Foliage  said  to 
be  poisonous  to  young  browsing  animals. 

IV.    EPIGJEA,  L. 

Prostrate  or  trailing  shrubs.  Steins  rusty-downy,  6-12  in. 
long.  Leaves  alternate,  leathery,  evergreen.  Flowers  in 
bracted,  terminal  close  racemes  or  clusters.  Calyx  5-parted, 
persistent.  Corolla  salver-shaped,  5-lobed.  Stamens  10,  about 
the  length  of  the  corolla-tube.  Ovary  5-lobed ;  style  columnar ; 
stigma  5-lobed.  Fruit  a  globose,  hairy,  5-celled,  many-seeded 
capsule.* 

1.  E.  repens,  L.  GROUND  LAUREL,  TRAILING  ARBUTUS,  MAY- 
FLOWER. Stems  creeping,  the  young  twigs  ascending.  Leaves  oval 
or  somewhat  heart-shaped,  entire,  netted-veined,  smooth  above, 
rough-hairy  beneath ;  petioles  short,  rough-hairy.  Racemes  shorter 
than  the  leaves.  Flowers  white  to  bright  pink,  £  in.  broad,  very 
fragrant.  In  dry  woods,  often  covering  considerable  areas.* 

V.    ARCTOSTAPHYLOS,  Adans. 

Shrubs.  Leaves  alternate,  evergreen.  Flowers  pinkish  or 
nearly  white,  in  terminal,  bracted  racemes.  Calyx  4-5-parted, 
persistent.  Corolla  4-5-lobed,  the  lobes  recurved.  Ovary 
5-10-celled,  each  cell  containing  1  ovule.  Fruit  a  berry-like 
stone-fruit,  with  5-10  nutlets. 

1.  A.  Uva-ursi,  Spreng.  BEARBERRY.  In  trailing  clumps,  the 
branches  1-2  ft.  high.  Leaves  evergreen,  finely  woolly,  obovate  or 
spatulate,  entire,  very  leathery.  Racemes  few-flowered,  very  short. 
Corolla  urn-shaped,  the  teeth  hairy  within.  Berry  red,  ^  in.  in 
diameter.  Rocks  and  dry  hilltops,  especially  N. 

VI.     GAYLUSSACIA,  HBK. 

Low,  branching  shrubs,  mostly  resinous-dotted.  Leaves 
serrate  or  entire.  Flowers  small,  white  or  pink,  in  lateral, 
bracted  racemes,  nodding ;  pedicels  usually  2-bracteolate. 
Calyx-tube  short,  obconic,  the  lobes  persistent.  Corolla 
ovoid  to  bell-shaped,  5-lobed,  the  lobes  erect  or  recurved. 
Stamens  equal,  usually  included  ;  anthers  awnless.  Fruit  a 
10-seeded,  berry-like  stone-fruit.* 


170  FOUNDATIONS   OF  BOTANY 

1.  G.  frondosa,  Torr.  and  Gray.     TANGLEBERRY.     An  erect  shrub, 
1-3   ft.   high ;  branches   spreading,  slender,   gray,  slightly  downy. 
Leaves  entire,  oblong  or  obovate,  obtuse,  thin,  smooth  and  green 
above,  paler,  downy,  and  with  resinous  dots  beneath ;  petioles  short. 
Racemes  few-flowered.      Corolla   small,    greenish-pink,    short-bell- 
shaped;  bracts  small,   oblong,   shorter   than   the    pedicels.     Berry 
depressed-globose,    dark   blue,  with  bloom,  sweet,  about   ^  in.    in 
diameter.     On  low  ground.* 

2.  G.    resinosa,    Torr.  and    Gray.      HUCKLEBERRY.     A    much- 
branched,  stiff   shrub,  1-3    ft.  high,   slightly   downy  when   young. 
Leaves  oval  or  oblong,  rarely  obovate,  obtuse  or  nearly  so,  entire, 
covered  when  young  with  little  resinous  particles.     Flowers  in  short, 
one-sided  racemes.     Corolla  at  first  conical-ovoid,  becoming  after- 
ward nearly   cylindrical,  pink  or  reddish.      Fruit    (in  the   typical 
form)  black,  with  no  bloom,  sweet,  the  seed-like  nutlets  rather  large. 
Woods  and  pastures  in  sandy  soil. 


VII.    VACCINIUM,  L. 

Shrubs  or  small  trees.  Leaves  entire  or  serrulate,  often 
leathery  and  evergreen.  Mowers  terminal  or  lateral,  clus- 
tered or  solitary,  nodding.  Pedicels  2-bracteolate.  Calyx- 
tube  globose  or  hemispherical,  4-5-lobed,  persistent.  Corolla 
urn-shaped,  cylindrical  or  bell-shaped,  4-5-lobed.  Stamens 
twice  as  many  as  the  lobes  of  the  corolla,  anthers  awned  or 
awnless.  Ovary  4-5-celled,  each  cell  partially  divided  by  a 
partition,  which  makes  the  ovary  appear  8-10-celled  ;  style 
slender ;  stigma  simple.  Fruit  a  many-seeded  berry.* 

1.  V.  corymbosum,  L.     HIGH-BUSH  BLUEBERRY.     An  erect  shrub, 
6-12  ft.  high ;  branches  stiff,  young  twigs  minutely  warty.     Leaves 
deciduous,  oval  to  ovate-lanceolate,  acute,  margins  bristly,  serrulate, 
smooth   or  downy,   short-petioled.     Racemes  numerous,  appearing 
with    or   before   the   leaves.     Bracts    oval    or   oblong,   deciduous. 
Flowers   white   or   pink.     Corolla  almost  as   long  as  the  pedicel, 
cylindrical.     Berry  globose,  blue  or  black,  flavor  slightly  acid,  pleas- 
ant. Common  in  woods  and  thickets,  whole  plant  extremely  variable.* 

2.  V.  pennsylvanicum,  Lam.     DWARF  BLUEBERRY,  Low  BLUE- 
BERRY.    Low  (usually  6-12  in.  high,  sometimes  2  ft.  high)    and 
smooth,  with  warty,  green   branches.     Leaves   oblong   or   oblong- 
lanceolate,  sharply    serrate,  with   little   bristle-pointed   teeth,  both 
sides  smooth  and  shining  except  for  down  occasionally  on  the  mid- 
rib and  veins  below,  pointed  at  both  ends.     Flowers  few  in  a  clus- 
ter, longer  than  their  minute  pedicels.     Corolla  oblong,  bell-shaped, 


DICOTYLEDONOUS   PLANTS  171 

a  little  narrowed  at  the  throat,  white  or  pinkish.  Berry  blue,  with 
much  bloom,  ripening  earlier  than  the  other  eatable  species,  sweeter 
than  No.  1,  but  not  so  high-flavored.  In  dry  or  sandy  soil,  espe- 
cially N. 

3.  V.  stamineum,  L.     DEERBERRY,  SQUAW  HUCKLEBERRY.     An 
erect  shrub,  3—10  ft.  high ;  branches  widely  spreading,  twigs  smooth 
or   minutely  downy.     Leaves  deciduous,  oval  or   oblong,  acute  or 
taper-pointed   at  the  apex,  obtuse  or  slightly  heart-shaped  at  the 
base,   firm,    smooth,    and   green   above,    pale    and   slightly   downy 
beneath,  petioled.     Racemes  with  leaf-like  bracts.     Flowers  numer- 
ous, drooping,  on   jointed,  slender   pedicels.     Corolla   bell-shaped, 
purplish-green,  2-awned  anthers  and  style  projecting.     Berry  glo- 
bose or  pear-shaped,  inedible.     Dry  woods.* 

4.  V.  arboreum,    Marsh.     FARKLEBERRY.      Tree-like,    sometimes 
30  ft.  high ;  bark  gray  ;  twigs  slender,  smooth  or  downy.     Leaves 
deciduous,  ovate  or  oval,  mucronate,   entire   or  glandular-dentate, 
leathery,  green  above,  often  slightly  downy  beneath.     Racemes  with 
leaf-like  bracts;  pedicels  slender,  drooping.     Corolla  campanulate, 
white.     Anthers  included ;  style  projecting.     Berry  globose,  black, 
mealy,  ripening  in  winter.     Common  in  dry,  open  woods.* 

5.  V.  macrocarpon,  Ait.     CRANBERRY.     Stems  creeping,  thread- 
like, 1-3  ft.  or  more  in  length,  the  branches  not  quite  erect,  some- 
times 8  in.  high.     Leaves  usually  oval  or  oblong,  obtuse,  thickish, 
evergreen,  the   younger   ones  with   the   margins   somewhat   rolled 
under.     Flowers  nodding.     Petals  strongly  reflexed,   deep  rose-red 
inside  at  the  base,  pale  pinkish  or  almost  white  at  the  tips.     Sta- 
mens with  the  filaments  hardly  £  as  long  as  the  anthers.     Fruit  red 
or  reddish-purple,  ellipsoidal  or   nearly   globose,  very  acid,   much 
valued  for  sauce,  pies,  and  jellies.     Common  in  peat-bogs  and  wet 
meadows  N. 


76.   PRIMULACE^.     PRIMROSE  FAMILY. 

Herbs,  with  simple  leaves,  often  most  or  all  of  them  radi- 
cal. Flowers  perfect  and  regular,  generally  gamopetalous. 
Stamens  commonly  5,  inserted  on  the  corolla,  opposite  its 
lobes.  Pistil  consisting  of  a  single  stigma  and  style  and  a 
(generally  free)  1-celled  ovary,  with  a  free  central  placenta. 

I.  DODECATHEON,  L. 

A  smooth,  perennial  herb,  with  a  cluster  of  oblong  or  spatu- 
late  root-leaves,  fibrous  roots,  and  an  unbranched  scape, 


172  FOUNDATIONS   OF  BOTANY 

leafless  except  for  an  involucre  of  small  bracts  at  the  summit, 
with  a  large  umbel  of  showy,  nodding  flowers.  Calyx  deeply 
5-cleft,  with  reflexed,  lanceolate  divisions.  Tube  of  the 
corolla  very  short,  the  divisions  of  the  5-parted  limb  strongly 
reflexed.  Filaments  short,  somewhat  united  at  the  base ; 
anthers  long,  acute,  and  combining  to  form  a  conspicuous  cone. 

1.  D.  meadia,  L.  SHOOTING  STAR,  INDIAN  CHIEF.  Corolla 
varying  from  rose-color  to  white.  In  rich  woods  in  most  of  the 
Middle  and  Southern  States.  Often  cultivated. 


II.     PRIMULA,  L. 

Low,  perennial  herbs,  with  much-veined  root-leaves  ;  scapes, 
each  bearing  an  umbel  of  flowers,  which  are  often  showy. 
Calyx  tubular,  decidedly  angled,  5-cleft.  Corolla  more  or  less 
salver-shaped,  with  the  tube  widened  above  .the  insertion  of 
the  stamens  ;  the  5  lobes  of  the  limb  often  notched  or  cleft. 
Stamens  5,  not  protruding  outside  the  corolla-tube.  Capsule 
egg-shaped,  splitting  at  the  top  into  5  valves,  each  of  which 
may  divide  in  halves. 

1.  P.  grandiflora,  Lam.     TRUE  PRIMROSE.     Leaves  spatulate  or 
obovate-oblong.     Flowers  rising  on  separate  slender  pedicels  from 
the  leaf-axils.     Corolla  originally  pale  yellow,  but  varying  to  white, 
red,  and  many  intermediate  shades,  with  a  broad,  flat  limb.     Culti- 
vated from  Europe. 

2.  P.  sinensis,  Sabine.     CHINESE    PRIMROSE.     A  rather  coarse, 
downy  plant.     Leaves  round-heart-shaped,  more  or  less  lobed  and 
cut,  long-petioled.     Flowers  large,  in  umbels,  usually  rose-color  or 
white.     Calyx  large,  inflated  and  conical.     Cultivated  as  a  house 
plant. 

III.     TRIENTALIS,  L. 

Low,  smooth,  perennial  herbs,  with  slender,  erect,  un- 
branched  stems.  Leaves  lanceolate,  ovate,  or  oblong,  mostly 
in  a  whorl  at  the  summit  of  the  stem.  Flowers  one  or  few, 
terminal,  on  slender  peduncles,  small,  white  or  pink.  Sepals 
narrow  and  spreading.  Corolla  wheel-shaped,  with  usually 
7  taper-pointed  segments.  Ovary  globose ;  style  thread-like. 
Capsule  globose,  many-seeded. 


DICOTYLEDONOUS  PLANTS  173 

1.  T.  americana,  Pursh.  STAR-FLOWER,  CHICKWEED  WINTER- 
GREEN.  Spreading  by  long  and  slender  rootstocks,  branches  erect, 
stem-like,  3-9  in.  high.  Leaves  very  thin,  pale  green,  pointed  at  both 
ends.  Flowers  white.  Capsules  white,  marked  off  into  polygonal 
sections,  each  corresponding  to  1  seed.  Cold  woods,  common  N. 

IV.  STEIRONEMA,  Raf. 

Perennial  herbs.  Leaves  opposite  or  whorled,  simple, 
entire.  Flowers  yellow,  axillary  or  racemose,  on  slender 
peduncles.  Calyx-tube  5-parted,  persistent.  Corolla  5-parted, 
wheel-shaped,  tube  very  short  or  none,  the  lobes  denticulate 
at  the  apex,  and  in  the  bud  each  one  enclosing  a  stamen. 
Stamens  5,  distinct  or  slightly  united  at  the  base,  sterile  rudi- 
ments often  alternating  with  them.  Ovary  globose  ;  style 
slender.  Fruit  a  globose,  5-valved,  few  or  many-seeded 
capsule.* 

1.  S.  ciliatum,  Raf.  FRINGED  LOOSESTRIFE.  Stems  erect,  slen- 
der, simple,  or  branched,  1-3  ft.  high.  Leaves  opposite,  ovate  to 
ovate-lanceolate,  acute  at  the  apex,  rounded  at  the  base,  margins  and 
petioles  hairy-fringed;  flowers  solitary  on  axillary  peduncles,  f-1  in. 
broad  ;  petals  broadly  ovate  or  roundish,  denticulate  ;  calyx  shorter 
than  the  capsule.  Woods  arid  thickets.* 

V.  LYSIMACHIA,  Tourn. 

Perennials,  with  opposite  or  whorled  entire  leaves,  which 
are  often  dotted.  Calyx  5-6-parted.  Corolla  wheel-shaped, 
with  its  divisions  commonly  nearly  separate.  Stamens  gen- 
erally somewhat  monadelphous  at  the  base. 

1.  L.  quadrifolia,  L.  FOUR-LEAVED  LOOSESTRIFE.  Stem  erect  and 
simple,  1-2  ft.  high,   hairy.      Leaves  whorled,  most  frequently  in 
fours,  broadly  lanceolate.     Flowers  small,  axillary,  and  solitary,  on 
long  and  slender  peduncles.     Damp  or  sandy  soil. 

2.  L.  stricta,  L.      BULB-BEARING  LOOSESTRIFE.     Stems  1-2  ft. 
high,  finally  branching,  frequently  producing  bulblets  in  the  leaf- 
axils  after  flowering.    Leaves  abundant,  generally  opposite,  narrowly 
lanceolate.     Flowers  small,  pediceled,  in  a  long,  terminal  raceme. 
Low  or  swampy  ground. 


174  FOUNDATIONS   OF  BOTANY 


VI.     ANAGALLIS,  Tourn. 

Annual  or  perennial  herbs  ;  stems  erect  or  diffuse.  Leaves 
opposite  or  whorled.  Flowers  axillary,  peduncled.  Calyx- 
tube  5-parted,  persistent.  Corolla  wheel-shaped,  5-parted, 
longer  than  the  calyx.  Stamens  5,  inserted  on  the  base  of 
the  corolla  ;  filaments  bearded.  Ovary  globose  ;  style  slen- 
der ;  stigma  knobbed.  Fruit  a  many-seeded  capsule,  the  top 
coming  off  like  a  lid.* 

1.  A.  arvensis,  L.  POOR  MAN'S  WEATHER-GLASS,  PIMPERNEL. 
Annual;  stem  spreading,  widely  branched,  4-angled,  smooth,  4-12  in. 
long.  Leaves  opposite,  sessile,  ovate,  black-dotted  beneath.  Flowers 
on  peduncles  longer  than  the  leaves,  nodding  in  fruit,  corolla  fringed 
with  glandular  hairs,  longer  than  the  acute  calyx-lobes,  bright  red, 
opening  in  sunshine.  Capsule  globose,  tipped  by  the  persistent 
style.  Introduced,  and  common  in  fields  and  gardens.* 


77.    EBENACEJE.     EBONY  FAMILY. 

Trees  or  shrubs.  Leaves  alternate,  entire,  pinnately  veined, 
without  stipules.  Flowers  often  dioecious.  Calyx  free  from 
the  ovary,  persistent.  Stamens  2-4  times  as  many  as  the 
divisions  of  the  corolla.  Ovary  3-12-celled  ;  ovules  1  or  2  in 
each  cell.  Fruit  a  berry.  Mostly  tropical  plants. 

I.    DIOSPYROS,  L. 

Flowers  dioecious  or  somewhat  monoecious,  the  staminate 
ones  in  cymes,  the  pistillate  ones  axillary  and  solitary.^  Calyx 
4-6-lobed.  Corolla  4-6-lobed.  Stamens  in  the  staminate 
flowers  usually  16,  in  the  pistillate  ones  8,  imperfect.  Fruit 
large,  with  the  persistent  calyx  attached  to  its  base,  4-8-seeded. 

1.  D.  virginiana,  L.  PERSIMMON.  Trees,  with  rough,  black  bark 
and  very  hard  wood.  Leaves  oval  or  ovate-oblong,  acute  or  acuminate 
at  the  apex,  rounded  or  slightly  cordate  at  the  base,  entire  and  dark 
green,  smooth  above,  pale  and  often  downy  beneath,  short-peti- 
oled,  deciduous;  flowers  yellowish-white,  the  parts  mostly  in  4's ; 
fruit  globose,  edible  when  ripe,  very  astringent  when  green ;  seeds 
large,  compressed,  often  wanting.  Fruit  ripening  late  in  the  fall. 
Common,  in  old  fields  and  along  roadsides  S.  and  S.W.* 


DICOTYLEDONOUS  PLANTS  175 


78.   OLEACE^.     OLIVE  FAMILY. 

Shrubs  or  trees.  Leaves  opposite,  simple  or  odd-pinnate, 
without  stipules.  Flowers  in  forking  cymes,  small,  white  or 
greenish,  perfect  or  imperfect.  Calyx  free  from  the  ovary, 
4-lobed  or  wanting.  Corolla  hypogynous,  regular,  4-parted  or 
of  4  separate  petals,  sometimes  wanting.  Stamens  2,  borne 
on  the  petals  or  hypogynous.  Ovary  2-celled.  Fruit  1-2- 
celled,  each  cell  1 -seeded,  rarely  2-seeded. 


I.     FRAXINUS,  Tourn. 

Deciduous  trees.  Flowers  dioecious.  Petals  wanting  (in 
our  species).  Stamens  2,  hypogynous.  Fruit  a  1-2-celled 
key,  each  cell  1-seeded. 

1.  F.  americana,  L.     WHITE  ASH.     A  large  tree;   bark   rough, 
gray ;  wood  hard,  strong,  elastic  ;  twigs  and  petioles  smooth.    Leaflets 
usually  7,  ovate  to  ovate-lanceolate,  taper-pointed  at  the  apex,  rounded 
or  obtuse  at  the  base,  entire  or  slightly  serrate,  smooth  above,  often 
downy  beneath,  short-stalked.     Flowers  mostly  dioecious.     Calyx  of 
the  pistillate  flowers  persistent.     Key  l|—2  in.  long,  winged  only 
at  the  apex  ;  wing  spatulate  or  oblanceolate.      In  rich  woods  and 
swamps.* 

2.  F.  pubescens,  Lam.     RED  ASH.     A  small  tree;   bark  rough, 
dark  gray ;  twigs  and  petioles  densely  velvety-downy.     Leaflets  5-9, 
oblong-ovate  to  ovate-lanceolate,  taper-pointed  at  the  apex,  narrowed 
into  a  short  stalk  at  the  base,  finely  serrate,  smooth  above,  velvety- 
downy  beneath.     Calyx  of  the  pistillate  flowers  persistent.    Key  1|- 
2  in.  long,  the  wing  somewhat  extended  along  the  sides,  oblanceolate 
or  spatulate,  often  notched.     Swarnps  and  moist  soil.* 

3.  F.    platycarpa,    Michx.     WATER    ASH.     A  small  tree ;    wood 
soft,  light  and  weak ;  twigs  smooth  or  downy.     Leaflets  5-7,  ovate 
or  elliptical,  acute  at  the  apex,  acute  or  obtuse  at  the  base,  entire  or 
slightly  serrate,  smooth  or  slightly  downy,  stalked.     Flowers  dioe- 
cious.    Calyx  persistent.     Key  often  3-angled  or  3-winged,  wings 
running  nearly  to  the  base,  oblong  or  oval,  pinnately  veined.     In 
swamps  and  wet  soil.* 

4.  F.  quadrangulata,  Michx.    BLUE  ASH.     A  large  tree,  with  wood 
heavy,  but  not  as  tough  as  No.  1 ;  the  most  vigorous  twigs  usually 
square.    Leaflets  7-9,  with  short  stalks,  somewhat  ovate  or  lanceolate, 
acute,  sharply  serrate.    Fruit  winged  to  the  base,  of  nearly  the  same 
width  throughout,  narrowly  oblong.     Rich  woods,  especially  W. 


176  FOUNDATIONS   OF   BOTANY 


II.     FORSYTHIA,  Vahl. 

Shrubs.  Leaves  opposite  or  in  threes,  appearing  later  than 
the  flowers,  serrate.  Calyx  very  short,  deciduous.  Corolla 
yellow,  bell-shaped,  its  lobes  long  and  slender.  Stamens 
inserted  on  the  base  of  the  corolla-tube.  Pod  2-celled,  many- 
seeded. 

1.  F.  viridissima,  Lindl.     A  hardy  shrub,  with  branches  erect  or 
nearly  so.    Leaves  all  simple,  lance-oblong.    Calyx-lobes  half  as  long 
as  the  tube  of  the  corolla.     Lobes  of  the  corolla  spreading,  narrow- 
oblong,  style  equal  in  length  to  the  tube  of  the  corolla.     Cultivated 
from  Asia. 

2.  F.  suspensa,  Vahl.     A  hardy  shrub,  with  drooping  branches. 
Leaves  broadly  ovate,  often  some  of  them  with  3  leaflets,  the  lateral 
leaflets  small.    Lobes  of  the  corolla  longer,  broader,  and  more  spread- 
ing than  in  No.  1.    Style  shorter  than  the  tube  of  the  corolla.    Culti- 
vated from  Asia,  less  common  than  No.  1,  often  trained  over  porches 
and  arbors. 

HI.    SYRINGA,  L. 

Tall  shrubs,  forking  frequently,  from  the  failure  of  the 
terminal  buds  on  most  branches.  Leaves  simple,  entire. 
Flowers  in  close,  compound  panicles.  Calyx  4-toothed. 
Corolla  salver-shaped,  the  tube  long,  the  limb  4-lobed.  Pod 
dry,  flattened  at  right  angles  to  the  partition,  4-seeded. 

1.  S.  vulgaris,  L.    COMMON  LILAC.   A  strong-growing,  hardy  bush. 
Leaves   ovate,  somewhat   heart-shaped.     Flowers    sweet-scented,  in 
very   close,  large   clusters,  lilac   or   white.      Corolla-lobes   concave. 
Very  commonly  cultivated  from  Eastern  Europe. 

2.  S.  persica,  L.     PERSIAN  LILAC.     A   more   slender  and  less 
branched  shrub  than   No.  1.     Leaves   lance-ovate,  somewhat   nar- 
rowed or  tapering  at  the  base.     Flowers  in  rather  loose  clusters,  not 
very  sweet-scented,  pale  lilac  or  white.     Corolla-lobes  ovate,  some- 
what bent  inward.     Pods  linear.     Cultivated  from  Western  Asia, 
less  common  than  No.  1. 


IV.     CHIONANTHUS,  L. 

Shrubs  or  small  trees.  Leaves  simple,  opposite,  entire, 
petioled,  deciduous.  Flowers  in  panicles  borne  on  wood  of 
the  previous  season.  Calyx  small,  4-cleft,  persistent.  Corolla 


DICOTYLEDONOUS   PLANTS  177 

wheel-shaped,  4-parted,  the  lobes  long  and  linear.  Stamens 
2-4,  included,  inserted  on  the  base  of  the  corolla.  Style 
short ;  stigma  2-lobed.  Fruit  a  1-seeded  stone-fruit.* 

1.  C.  virginica,  L.  FRINGE-TREE.  A  small  tree,  with  smooth,  light 
gray  bark  and  spreading  branches.  Leaves  oval  to  oblong,  acute  or 
obtuse  at  each  end,  smooth  or  slightly  downy.  Panicles  large  and 
loose,  leafy-bracted,  appearing  with  the  leaves.  Flowers  on  slender, 
drooping  pedicels.  Petals  1  in.  or  more  in  length.  Fruit  ovoid,  pur- 
ple, J~f  in.  long.  Along  streams,  usually  on  light  soil.* 

V.    LIGUSTRUM,  Tourn. 

Shrnbs.  Leaves  simple,  opposite,  entire,  deciduous  or  some- 
times persistent.  *  Flowers  in  terminal  panicles  or  similar 
clusters,  white,  small.  Calyx  minutely  4-toothed  or  truncate. 
Corolla  funnel-form,  4-lobed.  Stamens  2,  short,  inserted  in  the 
tube  of  the  corolla.  Ovary  free,  2-celled,  2  ovules  in  each 
cell,  style  short.  Fruit  a  1-4-seeded,  globose  berry.* 

1.  L.  vulgare,  L.  PRIVET.  A  branching  shrub,  4-10  ft.  high; 
branches  long  and  slender.  Leaves  somewhat  leathery,  lanceolate  to 
obovate,  short-petioled,  tardily  deciduous.  Panicles  dense,  minutely 
downy.  Flowers  £  in.  wide,  fragrant.  Stamens  included.  Berries 
black.  Introduced  from  Europe  and  used  largely  for  hedges.* 


79.    GENTIAN ACE^.     GENTIAN  FAMILY. 

Annual  or  perennial  herbs.  Leaves  entire,  usually  oppo- 
site, sometimes  alternate,  without  stipules.  Flowers  regular, 
solitary  or  in  cymes.  Calyx  free  from  the  ovary,  4-8-toothed 
or  lobed.  Corolla  hypogynous,  wheel-,  bell-,  or  funnel-shaped, 
4-8-lobed.  Stamens  4—8,  inserted  on  the  corolla-tube ;  fila- 
ments thread-shaped;  anthers  facing  inwards.  Ovary  1-2- 
celled ;  ovules  many,  on  2  opposite  placentas.  Capsule  1-celled 
or  partially  2-celled,  2-valved,  many-seeded. 

I.    OBOLARIA,  L. 

A  low,  smooth,  purplish-green  perennial.  Flowers  axillary 
and  terminal,  Calyx  of  2  distinct,  spatulate,  bract-like  sepals. 


178  FOUNDATIONS   OF   BOTANY 

Corolla  tubular-bell-shaped,  4-lobed.  Stamens  short,  inserted 
at  the  notches  of  the  corolla.  Style  short ;  stigma  2-lipped. 
Capsule  ovoid,  more  or  less  2-4-celled  ;  seeds  very  minute 
and  numerous. 

1.  0.  virginica,  L.  PENNYWORT.  Stem  3-8  in.  high,  often  several 
from  the  same  root.  Leaves  somewhat  fleshy,  wedge-obovate  or 
somewhat  diamond-shaped,  often  truncate,  sessile.  Flowers  oppo- 
site or  terminal  in  threes,  nearly  sessile.  Corolla  pale  purple  or 
nearly  white.  Rich  woodlands,  among  dead  leaves. 

H.    MENYANTHES,  Tourn. 

Perennial,  scape-bearing  marsh  herbs.  Rootstock  creeping. 
Leaves  of  3  leaflets.  Flowers  racemed.  Calyx  5-parted. 
Corolla  fleshy,  funnel-shaped,  the  limb  5-parted.  Stamens  5, 
inserted  on  the  corolla-tube.  Disk  of  5  hypogynous  glands. 
Ovary  1-celled ;  style  thread-shaped ;  stigma  2-lobed.  Capsule 
globose,  many-seeded. 

1.  M.  trifoliata,  L.  BUCK-BEAN,  MARSH  TREFOIL.  Rootstocks 
stout  and  matted.  Leaflets  obtuse,  entire.  Flowers  f  in.  in  diam- 
eter, white  or  pinkish.  Bogs,  especially  IS". 


80.   APOCYNACE^.     DOGBANE  FAMILY. 

Trees,  shrubs,  or  herbs,  with  milky  juice,  often  climbing. 
Leaves  usually  opposite,  rarely  whoiied;  entire,  nearly  or 
quite  without  stipules.  Flowers  regular,  solitary,  or  in  cymes. 
Calyx  4-5-cleft.  Corolla  hypogynous,  funnel-,  salver-,  or  bell- 
shaped,  sometimes  with  scales  in  the  throat.  Stamens,  4-5, 
borne  on  the  corolla-tube  or  throat;  filaments  very  short; 
anthers  somewhat  attached  to  the  stigma.  Ovary  of  2  car- 
pels, free  or  somewhat  united ;  style  short ;  stigma  entire 
or  2-cleft.  Fruit  of  2  many-seeded  pods  (in  the  genera  here 
described). 

I.    AMSONIA,  Walt. 

Perennial  herbs ;  stem  erect,  branched.  Leaves  alternate. 
Flowers  in  terminal  panicles.  Calyx  small,  5-parted.  Corolla 


DICOTYLEDONOUS  PLANTS  179 

small,  pale  blue,  funnel  or  salver  form,  downy  within.  Sta- 
mens inserted  above  the  middle  of  the  tube,  included.  Ovary 
of  2  carpels,  united  at  the  top  by  the  slender  style;  stigrna 
globose,  surrounded  by  a  cup-shaped  appendage.  Fruit  2 
slender,  erect,  many-seeded  follicles  ;  seeds  without  tufts  of 
hairs.* 

1.  A.  tabernsemontana,  Walt.  AMSONIA.  Stem  smooth  and  gla- 
brous, branched  above,  2-3  ft.  high.  Leaves  lanceolate,  entire, 
acuminate  at  the  apex,  acute  at  the  base,  smooth  above,  with  a 
bloom  or  slightly  downy  beneath,  short-petioled.  Flowers  numer- 
ous, on  bracted  pedicels.  Corolla-tube  slender,  smooth  or  sometimes 
downy  above,  the  lobes  narrow,  as  long  as  the  tube.  Follicles 
slender,  spreading,  4-6  in.  long;  seeds  downy.  Swamps  and  wet 
ground  S.* 

II.    VINCA,  L. 

Perennial  herbs  or  small,  slender  shrubs ;  juice  not  percep- 
tibly milky.  Leaves  evergreen.  Flowers  solitary,  white, 
blue,  or  purple.  Calyx  5-parted,  lobes  taper-pointed,  glandu- 
lar inside  at  the  base.  Corolla  salver-shaped,  thickened  at 
the  throat,  5-lobed.  Stamens  5,  inserted  on  the  upper  or 
middle  part  of  the  corolla-tube.  Ovary  of  2  carpels.  Pods 
2,  slender,  cylindrical,  many-seeded. 

1.  V.  minor,  L.  PERIWINKLE.  Stem  slender,  trailing,  often  root- 
ing at  the  nodes,  1-3  ft.  long.  Leaves  ovate,  acute  at  the  apex, 
short-petioled,  bright  green.  Flowers  axillary,  solitary,  1  in.  wide. 
Calyx  with  linear  lobes  nearly  as  long  as  the  inflated  tube  of  the 
blue  corolla.  Matured  pods  slender,  slightly  divergent.  Introduced 
from  Europe  and  common  in  gardens.* 


m.    APOCYNUM,  Tourn. 

Perennial  herbs ;  stems  with  very  tough  bark,  branched 
above.  Leaves  opposite,  entire.  Flowers  in  terminal  and 
axillary  bracted  cymes.  Calyx  small,  5-parted,  lobes  acute. 
Corolla  bell-shaped,  5-lobed,  with  a  small,  scale-like  append- 
age at  the  base  of  each  lobe.  Stamens  5,  distinct,  inserted 
on  the  base  of  the  corolla-tube.  Ovaries  2,  distinct,  united 
by  the  styles ;  stigma  obtuse,  2-lobed.  Pods  long,  slender, 
many-seeded  ;  seeds  with  a  tuft  of  hairs.* 


180  FOUNDATIONS  0$  BOTANY 

1.  A.  cannabinum,  L.     INDIAN  HEMP.     Stem  erect,  smooth,  with 
numerous   erect   or   ascending   branches.     Leaves   oval   to  oblong, 
miicronate  at  the  apex,  rounded  at  the  base,  downy  beneath,  short- 
petioled.    Cymes  terminal,  compact,  shorter  than  the  leaves.    Flowers 
are  on  short,  bracted  pedicels,  greenish-white,  about  |  in.  broad. 
Calyx-lobes   lanceolate,  nearly  as  long  as  the  tube  of   the  corolla. 
Corolla-lobes   erect.      Pods  very  slender,  tapering,   3-4    in.    long. 
Along  fences  and  in  thickets.* 

2.  A.  androsaemifolium,   L.      DOGBANE.      Plant    2-3    ft.    high, 
usually    smooth,    purplish,    the   branches    spreading    and    forking. 
Leaves  2-3  in.  long,  acute,  mucronate,  petioles  about  £  in.  long. 
Cymes    mostly    terminal,    few-flowered.      Calyx-teeth    lance-ovate, 
about  half  as  long  as  the  corolla-tube.     Corolla  pale  red  or  whitish, 
its   lobes   recurved.     Pods  stouter  than  in  No.  1.     Roadsides  and 
clearings,  common. 

IV.    NERIUM,  L. 

Shrubs.  Leaves  mostly  whorled  in  threes.  Flowers  in  termi- 
nal cymes.  Calyx  small,  lobes  acute.  Corolla  salver-form, 
the  throat  of  the  tube  crowned  with  cleft  or  cut-fringed 
scales.  Stamens  5,  short,  included  ;  anthers  tipped  with  a 
hairy  bristle.  Ovary  of  2  carpels  ;  style  short.  Pods  erect, 
seeds  with  a  tuft  of  hairs.* 

1.  N.  Oleander,  L.  OLEANDER.  Stem  erect,  diffusely  branched 
from  below,  4-10  ft.  high.  Leaves  narrowly  elliptical,  acute  at  each 
end,  thick  and  leathery,  short-petioled.  Flowers  showy,  in  large 
clusters,  red  or  white,  often  double ;  scales  of  the  crown  3-4-pointed 
unequal  teeth ;  pods  spindle-shaped,  3-4  in.  long.  Introduced  from 
Palestine,  common  in  cultivation.* 


81.   ASCLEPIADACEJE.     MILKWEED  FAMILY. 

Shrubs  or  herbs,  often  twining ;  juice  usually  milky. 
Leaves  generally  opposite  or  whorled,  entire,  without  stipules. 
Flowers  regular.  Calyx  5-parted.  Corolla  5-parted.  Sta- 
mens 5  ;  the  filaments  usually  cohering  around  the  styles, 
often  with  hood-like  appendages,  each  with  an  incurved  horn 
borne  on  the  stamen-tube  and  forming  a  crown  around  the 
stigma  (Fig.  20,  A) ;  anthers  pressing  against  the  lobes  of  the 
stigma  ;  the  pollen  clinging  together  in  tough,  waxy  or  fine- 


DICOTYLEDONOUS  PLANTS  181 

grained  masses.  Ovary  free  from  the  calyx-tube,  of  2  carpels, 
more  or  less  united  below  but  unconnected  above ;  styles  2  ; 
stigmas  5-angled  ;  ovules  several-many.  Fruit  consisting  of 
1  or  2  pods.  The  flowers  are  very  highly  specialized  for 
pollination  by  insects  (see  below,  under  Asclepias). 

I.     ASCLEPIAS,  L. 

Perennial  herbs.  Flowers  in  simple  (usually  many-flow- 
ered) umbels.  Calyx  small,  5-parted,  its  lobes  reflexed. 
Corolla  deeply  5-parted,  with  reflexed  lobes  ;  crown  of  hoods 
and  horns  conspicuous  (Fig.  20,  A,  B).  Stamens  with  their 
filaments  united  into  a  tube  around  the  pistil  and  anthers 
adnate  to  the  stigma  (Fig.  20,  D,  E)  ;  anther-cells  2,  each  cell 
containing  an  elongated,  pear-shaped,  tough  mass  of  pollen,  a 
mass  from  one  anther  always  paired  with  one  from  the  adjoin- 
ing anther  and  each  two  together  suspended  from  one  of  the 
5  split  glands  on  the  angles  of  the  stigma  (Fig.  20,  D,  E). 
Ovaries  2 ;  styles  very  short.  Pods  2  or  sometimes  1  and  the 
other  undeveloped.  Seeds  flat,  each  with  a  tuft  of  long,  silky 
hairs.  The  flowers  are  pollinated  by  insects,  which  get  their 
feet  entangled  in  the  clefts  of  the  glands  (Fig.  20,  g)  and 
then  carry  off  the  pollen-masses.  (See  Mtiller,  The  Fertiliza- 
tion of  Flowers,  pp.  396-399  inclusive.) 

1.  A.  purpurascens,  L.     PURPLE  MILKWEED.     Stem  1-3  ft.  high, 
somewhat  branched  above.     Leaves  4-6  in.  long,  elliptical  or  nearly 
so,  the  upper  ones  taper-pointed,   slightly  velvety  beneath,  short- 
petioled.     Umbels  terminal.     Flowers  %  in.  long,  dark  purple ;  pedi- 
cels  shorter  than  the  peduncle ;  horn  broadly  scythe-shaped,  with 
the  point  bent  sharply  inward.     Dry  soil. 

2.  A.    Cornuti,    Decaisne.     COMMON    MILKWEED.     Stem    stout, 
3-4  ft.  high,  finely  downy.     Leaves  4-8  in.  long,  oblong  or  nearly 
so,  downy  beneath.     Umbels  terminal  or  nearly  so.     Flowers  vary- 
ing from   purple  or  greenish-purple  to  whitish,  numerous,  with  a 
strong,  sweet,  but  sickening  odor.     Hoods  with  a  tooth  on  each  side 
of  the  stout  horn.     Common  in  rich  soil. 

3.  A.    phytolaccoides,   Pursh.     POKE-LEAVED  MILKWEED.     Stem 
rather  slender,  3-5  ft.  high.     Leaves  6-9  in.  long,  ovate  or  oval- 
lanceolate,    taper-pointed,    short-petioled.      Umbels   several,    mostly 
lateral;    pedicels    slender   and    drooping.     Lobes    of    the    corolla 


182 


FOUNDATIONS   OF   BOTANY 


greenish ;    hoods  white,  with    2    teeth ;    horns  with  an   awl-shaped 
point  extending  far  out  of  the  hoods.     Damp  thickets  N.  and  E. 

4.  A.  variegata,  L.  WHITE  MILKWEED.  Stem  stout,  leafless 
and  smooth  below,  leafy  and  downy  in  lines  above.  Leaves  oppo- 
site, the  middle  ones  sometimes  in  fours,  petioled,  ovate  to  obovate, 


FIG.  20.  —  Flower  of  Asclepias  Cornuti. 

A,  entire  flower  ;  B,  vertical  section  ;  C,  diagram ;  D,  details  of  pollen-masses 
and  glands,  ca,  calyx  ;  c,  corolla ;  hd,  hood  ;  hn,  horn  ;  a,  anther  ;  s,  stig- 
ma ;  o,  ovary  ;  g,  gland ;  p,  pollen-mass.  (All  considerably  enlarged.) 

cuspidate,  smooth  on  both  sides,  pale  beneath,  edges  slightly  crenate. 
Umbels  1-5,  compact,  downy,  1-2  in.  long  ;  pedicels  erect,  as  long 
as  the  peduncles.  Corolla  white,  often  purple  at  the  base ;  hoods 
roundish,  spreading,  a  little  longer  than  the  thick,  awl-pointed, 
incurved  horn.  Dry,  open  woods  E.  and  S.* 

5.  A.  quadrifolia,  L.     FOUR-LEAVED  MILKWEED.     Stem  slender, 
1^-2  ft.  or  more   high,  usually  leafless  below.     Leaves   in  1    or  2 


DICOTYLEDONOUS   PLANTS  183 

whorls  of  4  each,  near  the  middle  of  the  stem,  and  a  pair  or  two 
opposite,  thin,  slender-petioled,  2-4  in.  long,  ovate-lanceolate,  taper- 
pointed.  Umbels  usually  2,  sometimes  1,  with  slender  pedicels. 
Corolla-lobes  very  pale  pink  or  whitish  ;  hoods  white ;  horn  short, 
stout,  and  bent  inward.  Dry  woods  and  fence-rows. 

II.     HOYA,  R.  Br. 

Shrubby,  more  or  less  climbing,  smooth,  tropical  plants. 
Leaves  fleshy.  Calyx  5-cleft,  corolla  5-lobed,  wheel-shaped, 
its  divisions  thick  and  with  a  waxy  look.  Crown  of  5  spread- 
ing segments.  Pollen-masses  fastened  by  the  bases. 

1.  H.  carnosa,  R.  Br.  WAX  PLANT.  Stems  long  and  slender, 
rooting  and  trailing.  Leaves  oval  or  nearly  so,  thick,  dark  green. 
Flowers  in  close  umbels,  pink  or  whitish,  the  corolla-lobes  covered 
on  the  upper  surface  with  minute  projections.  Cultivated  from 
India  as  a  house  plant  and  in  conservatories. 


82.    CONVOLVULACE^.     MORNING-GLORY  FAMILY. 

Usually  twining  herbs  or  shrubs,  often  with  milky  juice. 
Leaves  alternate  (wanting  in  Cuscuta),  without  stipules. 
Flowers  variously  clustered,  rarely  solitary,  often  large  and 
showy.  Sepals  5.  Corolla  hypogynous,  regular,  tubular,  bell- 
shaped  or  funnel-shaped  ;  its  limb  more  or  less  5-lobed  or 
angled.  Stamens  5,  inserted  on  the  corolla-tube.  Ovary 
usually  2-4-celled  ;  style  slender,  2-4-cleft ;  ovules  1  or  2  in 
each  cell.  Capsule  1-4-celled,  2-4-valved  or  bursting  open 
across  the  base. 

I.     CALYSTEGIA,  R.  Br. 

Twining,  trailing,  or  nearly  erect  perennials.  Leaves  heart- 
shaped  or  arrow-shaped.  Flowers  peduncled,  axillary  and 
solitary.  Calyx  enclosed  in  2  large,  leaf-like,  usually  heart- 
shaped  bracts  ;  sepals  equal.  Corolla  bell-funnel-shaped,  its 
border  nearly  or  quite  entire ;  style  1 ;  stigmas  2.  Pod  1-celled 
or  partially  2-celled,  4-seeded. 

1.  C.  sepium,  R.  Br.  CREEPERS,  RUTLAND  BEAUTY.  Stem 
twining  or  sometimes  extensively  trailing.  Leaves  heart-arrow- 


184  FOUNDATIONS   OF   BOTANY 

shaped  or  somewhat  halberd-shaped,  the  lobes  at  the  base  trun- 
cate. Flowers  numerous  and  showy,  white  or  tinged  with  rose-color. 
Thickets  and  banks  of  streams,  often  cultivated. 

2.  C.  spithamaea,  Pursh.  Downy,  stem  6-12  in.  high,  erect  or 
reclining.  Leaves  oblong,  sometimes  heart-shaped  or  eared  at  the 
base.  Flowers  white.  In  sandy  soil. 

II.     CONVOLVULUS,  L. 

Herbs  or  shrubs,  with  stems  twining  or  nearly  erect.  Calyx 
not  bracted.  Corolla  broadly  funnel-form  or  bell-shaped. 
Stamens  not  projecting  from  the  corolla.  Style  1 ;  stigmas  2, 
thread-like  ;  ovary  and  pod  2-celled,  4-seeded. 

1.  C.  arvensis,  L.  BINDWEED.  A  perennial,  prostrate  or  climb- 
ing herb,  with  many  stems,  from  a  long,  slender  rootstock.  Leaves 
very  variable,  more  or  less  arrow-shaped,  1-3  in.  long.  Peduncles 
mostly  1-flowered ;  flowers  white  or  pinkish,  about  f  in.  long.  A 
weed  in  fields  E. ;  introduced  from  Europe. 

HI.     QUAMOCLIT,  Tourn. 

Twining  annual  herbs.  Sepals  5,  mostly  mucronate  or 
bristle-pointed.  Corolla  tubular,  with  a  narrow,  spreading 
border.  Stamens  projecting.  Style  1 ;  stigma  knobbed, 
2-lobed.  Pod  4-celled,  the  cells  1-seeded. 

1.  Q.  vulgaris,  Choisy.  CYPRESS  VINE.  Stem  slender,  smooth, 
twining  high.  •  Leaves  dark  green,  pinnately  cut,  the  divisions  lin- 
ear, smooth.  Peduncles  slender,  as  long  as  the  leaves,  1-5-flowered ; 
pedicels  thickened  upward.  Sepals  ovate  or  oblong,  mucronate. 
Corolla  bright  scarlet,  or  sometimes  yellowish-white,  salver-form,  the 
tube  1-1  ^  in.  long,  the  limb  flat  and  spreading,  £-|  in.  wide.  Cap- 
sule ovoid,  twice  the  length  of  the  sepals.  Common  in  gardens.* 

IV.    IMPOMCEA,  L. 

Annuals  or  perennials ;  steins  often  twining.  Flowers 
showy.  Calyx  not  bracted  at  the  base,  of  5  sepals.  Corolla 
bell-shaped  or  funnel-shaped,  twisted  in  the  bud.  Stamens 
not  projecting  from  the  corolla.  Style  slender ;  stigma 
knobbed,  2-lobed.  Fruit  a  2-3-celled  capsule.  [/.  purpurea, 
the  common  morning-glory,  blossoms  too  late  for  school  study. 
/.  Batatas,  the  sweet  potato,  seldom  flowers.] 


DICOTYLEDONOUS  PLANTS  185 

1.  I.    hederacea,   Jacq.     WILD   MORNING-GLORY.      Stems   hairy, 
twining.      Leaves   heart-shaped,   3-lobed.      Peduncles    1-3-flowered. 
Calyx  very  hairy  below.     Corolla   showy,   bluish-purple  or  white, 
Pod  usually  3-celled,  with  .2  seeds  in  each  cell.     A  weed  in  fields 
and  about  dwellings  ;  introduced  from  tropical  America. 

2.  I.  pandurata,  Meyer.     WILD  POTATO  VINE.     Perennial,  from 
a  very  large,  tuberous  root ;  stem  trailing  or  twining,  smooth  or 
slightly  downy,  5-10  ft.  long.     Leaves  broadly  heart-shaped,  with 
the  apex  slender  and  obtuse,  sometimes  fiddle-shaped  or  3-lobed ; 
petioles  slender.     Peduncles  longer  than  the  petioles,  1-5-flowered. 
Sepals  oblong,  obtuse,  smooth,  mucronate,  the  2  outer  ones  shorter. 
Corolla  white  with  a  purple  throat,  2—3  in.   wide,  lobes   pointed. 
Capsule  globose,  2-3-seeded,  the   seeds  woolly  011  the  angles.     On 
dry  or  damp,  sandy  soil,  along  fences,  railroad  embankments,  etc., 
common  S.  and  W.* 


83.   POLEMONIACEJE.     PHLOX  FAMILY. 

Annual  or  perennial  herbs,  rarely  shrubs.  Leaves  alter- 
nate or  the  lower  opposite,  without  stipules.  Flowers  in  ter- 
minal, forking  cymes.  Calyx  free  from  the  ovary,  5-lobed. 
Corolla  regular  or  nearly  so,  5-parted.  Stamens  5,  inserted 
on  the  corolla-tube,  usually  unequal.  Ovary  3-celled ;  style 
simple  ;  stigmas  3,  linear ;  capsule  3-celled,  the  cells  1-many- 
seeded. 

I.    PHLOX,  L. 

Perennial  or  rarely  annual  herbs ;  stems  erect  or  diffuse. 
Leaves  opposite,  or  the  upper  alternate,  entire,  without  stip- 
ules. Flowers  showy,  white  or  purple,  in  terminal  cymes 
or  panicles.  Calyx  cylindrical  or  funnel-form,  5-cleft,  the 
lobes  acute.  Corolla  salver-form,  the  tube  long  and  slender, 
the  limb  5-parted,  the  lobes  spreading,  entire  or  obcordate. 
Stamens  included,  unequal.  Ovary  3-celled,  style  slender. 
Capsule  ovoid,  3-celled,  1— few-seeded ;  seeds  wingless  or 
narrow-winged.* 

1.  P.  paniculata,  L.  GARDEN  PHLOX.  Perennial ;  stems  in 
clumps,  stout,  erect,  simple  or  branched  above,  2-4  ft.  high.  Leaves 
ovate-lanceolate  to  oblong,  taper-pointed  at  the  apex,  rounded  or 
cordate  at  the  base,  thin,  smooth,  veins  prominent  beneath.  Cymes 
numerous  and  compact,  forming  a  pyramidal  panicle  ;  pedicels  short. 


186  FOUNDATIONS   OF   BOTANY 

Calyx-teeth  long,  bristle-pointed.  Corolla  purple  to  white,  lobes 
round-obovate,  shorter  than  the  tube.  Capsule  longer  than  the 
calyx-tube.  In  rich  woods ;  often  cultivated.* 

2.  P.  maculata,  L.     WILD  SWEET  WILLIAM.    Stem  erect,  smooth 
or  nearly  so,  rather  slender,  purple-spotted,  1-2    ft.  high.     Lower 
leaves  lanceolate,  the  upper  ones  broader,  taper-pointed,  roundish 
or  heart-shaped  at  the  base.     Panicle  many-flowered,  narrow,  ellip- 
soidal.    Calyx-teeth  lanceolate,  hardly  acute.     Flowers  purple,  occa- 
sionally white.     Damp  woods  and  fields. 

3.  P.  pilosa,  L.     DOWNY  PHLOX.     Perennial;    stem  erect,  slen- 
der, simple  or  branched,  1-2  ft.  high.     Leaves  linear-lanceolate  to 
linear,    distant,   spreading,    long,    taper-pointed,   sessile ;    stern  and 
leaves  downy.     Cymes  corymbose,  loose.     Flowers  short-pediceled. 
Calyx  glandular-viscid,  the  teeth  shorter  than  the  tube  of  the  purple 
corolla,  bristle-pointed.    Corolla-tube  downy,  lobes  obovate.    Capsule 
twice  the  length  of  the  calyx-tube.     In  dry,  open  woods.* 

4.  P.    divaricata,    L.     WILD    BLUE    PHLOX.      Perennial;    stems 
erect  or  ascending  from  a  decumbent  base,  sticky-downy,  1  ft.  high. 
Leaves  distant,  lanceolate  to  oblong,  acute  at  the  apex,  rounded  at 
the  base,  sessile,  downy.    Cymes  corymbed,  loosely  flowered.     Calyx- 
teeth  awl-shaped,  longer  than  the  tube.     Corolla  bluish-purple,  |~| 
in.  long,  lobes  notched  at  the  apex,  as  long  as  the  tube.     Capsule 
oval,  shorter  than  the  calyx-teeth.     In  moist,  open  woods.* 

5.  P.  Drummondii,  Hook.     DRUMMOND'S  PHLOX.     Annual;  stem 
erect  or  ascending,  slender,  weak,  branching,  glandular-downy,  6-12 
in.  high.     Leaves  mostly  alternate,  lanceolate  to  oblong,  downy,  the 
upper  clasping  by  a  heart-shaped  base.     Corymbs  loose.     Flowers 
rather  long-pediceled.     Calyx-tube  short,  the  teeth  lanceolate,  bristle- 
pointed,  soon  recurved.     Corolla  purple  to  crimson  or  white,  orifice 
of  the  tube  usually  with  a  white  or  yellowish  star-like  ring,  lobes 
rounded  at  the  apex.     Ovary  3-seeded,  angles  of  the  seeds  winged. 
Introduced  from  Texas  and  common  everywhere  in  gardens.* 

6.  P.  subulata,  L.     GROUND  PINK,  Moss  PINK,  FLOWERING  Moss. 
Stems  perennial,  prostrate,  8-18  in.  long,  with  many  short,  somewhat 
upright   branches,   2-4  in.   high.      Leaves   linear-awl-shaped,   stiff, 
about  \  in.  long,   crowded,  with  clusters  of  smaller  ones  in  their 
axils.     Flower-clusters    3-6-flowered.     Corolla  pink-purple,   with  a 
darker  center,  or  sometimes  white.     Forms  dense  mats  on  rocky  or 
sandy  hillsides.     S.  and  W.  and  often  cultivated. 

II.     POLEMONIUM,  L. 

Perennial  herbs.  Leaves  alternate,  pinnate.  Flowers  cor- 
ymbed. Calyx  bell-shaped,  5-lobed.  Corolla  wheel-shaped, 
the  limb  with  5  obovate  lobes.  Stamens  borne  on  the  throat  of 


DICOTYLEDONOUS  PLANTS  187 

the  corolla,  the  filaments  enlarged  and  hairy  below.    Capsule 
ovoid,  3-celled,  many-seeded. 

1.  P.  reptans,  L.  JACOB'S  LADDER,  BLUE  VALERIAN,  BLUE- 
BELL. Stems  smooth,  branched,  and  leaning  over,  6-12  in.  high. 
Leaflets  usually  7  or  9,  about  an  inch  long.  Corolla  blue,  about 
3  times  as  long  as  the  calyx.  Capsule  3-seeded,  borne  on  a  short 
stalk  in  the  persistent  calyx.  Damp,  open  woods,  sometimes  culti- 
vated. 


84.   HYDROPHYLLACEJE.     WATERLEAF  FAMILY. 

Herbs,  usually  hairy.  Leaves  commonly  alternate  and 
alternate-lobed.  Flowers  with  their  parts  in  fives,  in  appear- 
ance not  unlike  those  of  the  following  family,  in  one-sided 
cymes,  which  are  coiled  up  at  first.  Calyx  free  from  the 
ovary,  usually  with  appendages  at  the  notches.  Corolla  often 
with  scales  or  nectar-bearing  folds  inside.  Stamens  borne  by 
the  corolla-tube.  Style  2-cleft,  or  styles  2.  Ovary  entire  and 
usually  1-celled.  Fruit  a  capsule,  2-valved,  4-many-seeded. 

I.    HYDROPHYLLUM,  Tourn. 

Coarse  perennials.  Leaves  large,  petioled.  Flowers  white 
or  pale  blue,  inconspicuous.  Calyx  5-parted,  sometimes  ap- 
pendaged  at  the  notches.  Corolla  bell-shaped,  5-cleft,  with 
5  double,  nectar-bearing  folds  inside.  Stamens  projecting,  the 
filaments  bearded.  Style  projecting;  ovary  covered  with 
bristly  hairs,  the  placentae  very  broad  and  fleshy,  enclosing 
the  ovules.  Capsule  globular,  1-4-seeded. 

1.  H.  macrophyllum,  Nutt.     A  coarse,  rough-hairy  plant,  about 
1  ft.  high,  from  scaly-toothed  rootstocks.    Leaves  oblong,  pinnate  and 
pinnately  cut,  the  divisions  mucronate,   obtuse,   coarsely   toothed. 
Flower-cluster  dense,  globular,  long-peduncled.     Flowers  about  £  in. 
long.     Calyx  little  or  not  at  all  appendaged,  its  lobes  broad  at  the 
base,  but  with  slender,  tapering  points.     Corolla  white.     Rich,  rocky 
woods  W.  and  S. 

2.  H.  virginicum,  L.    Nearly  smooth,  1-2  ft.  high,  stem  often  fork- 
ing at  the  base.     Leaves  of  the  stem  mostly  near  the  top,  pinnately 
cut  into  5-7  divisions ;  lobes  oval-lanceolate,  deeply  serrate,  the  lowest 


188  FOUNDATIONS   OF   BOTANY 

ones  distinct ;  petioles  of  the  radical  and  lower  leaves  4-8  in.  long. 
Flower-clusters  on  peduncles  longer  than  the  petioles  of  the  upper 
leaves,  from  the  axils  of  which  or  opposite  which  they  arise.  Flowers 
about  \  in.  long.  Calyx  not  appendaged,  its  lobes  narrowly  linear, 
bristly-margined.  Corolla  whitish,  with  purplish  veins.  Moist 
woods. 

3.  H.  appendiculatum,  Michx.  Hairy,  1-1^  ft.  high.  Stem-leaves 
palmately  5-lobed,  the  lobes  acute,  toothed,  lowest  ones  pinnately 
divided.  Flower-cluster  rather  loose.  Calyx  appendaged  at  the 
notches.  Corolla  blue.  Stamens  projecting  from  the  corolla  little 
or  not  at  all.  Moist  woods. 


H.    PHACELIA,  L. 

Herbs,  mostly  annual.  Leaves  alternate,  sometimes  simple, 
but  in  most  species  lobed  or  divided.  Flowers  in  one-sided 
clusters,  often  showy.  Calyx  5-parted,  without  appendages. 
Corolla  with  5  spreading  lobes.  Ovary  1-celled,  with  narrow 
placentae. 

1.  P.    tanacetifolia,   Benth.     A  tall,  hairy  annual.     Leaves   pin- 
nately cut.     Spikes  long,  densely  flowered.     Flowers  showy,  blue. 
Stamens  projecting.    Capsule  4-seeded.     Cultivated  from  California. 

2.  P.    Whitlavia,    Gray.     WHITLAVIA.     A   rather  coarse,   sticky 
annual.     Leaves  broad,  ovate,  coarsely  toothed,  petioled.     Flower- 
clusters  a  loose  raceme.     Flowers  showy,  about  1  in.  long,  blue  or 
sometimes  white.     Corolla  bell-shaped.     Stamens  and  style  project- 
ing.    Capsule  many-seeded.     Cultivated  from  California. 

3.  P.  Menziesii,   Torr.     EUTOCA.     A   much-branched,  somewhat 
rough  or  rough-hairy  plant,  3-12  in.  high.     Leaves  linear,  or  lanceo- 
late, entire  or  nearly  so.     Flowers  showy,  violet  or  white,  loosely 
panicled.     Capsule  many-seeded.     Cultivated  from  California. 


85.    BORR  AGIN  ACE  JE.     BORAGE  FAMILY. 

Mostly  herbs,  with  steins  and  foliage  roughened  with  stiff 
hairs.  Leaves  alternate  and  entire,  not  aromatic.  Flowers 
generally  in  a  coiled  inflorescence.  Calyx  5-parted.  Corolla 
hypogynous,  generally  5-lobed  and  regular.  Stamens  5, 
inserted  on  .the  corolla-tube.  Style  1;  ovary  commonly 
4-lobed,  ripening  into  4  l-seedM  nutlets, 


DICOTYLEDONOUS   PLANTS  189 


I.    HELIOTROPIUM,  Tourn. 

Herbs  or  low  shrubs.  Leaves  petioled.  Flowers  white, 
blue,  or  lilac,  in  one-sided,  curved  spikes.  Calyx  5-parted. 
Corolla  salver-shaped,  the  throat  open.  Anthers  almost  ses- 
sile. Style  short  ;  stigma  conical  or  knobbed.  Fruit  sepa- 
rating into  2  or  4  nutlets. 

1.  H.  peruvianum,  L.  COMMON  HELIOTROPE.  Somewhat  shrubby, 
much  branched.  Leaves  lance-ovate  or  somewhat  oblong,  veined 
and  much  wrinkled,  short-petioled.  Flowers  numerous,  in  a  cluster 
of  terminal  spikes,  bluish-purple  or  lavender,  very  sweet-scented,  the 
odor  not  unlike  that  of  vanilla.  Cultivated  from  Peru. 


II.     CYNOGLOSSUM,  Tourn. 

Coarse,  rough-hairy  or  silky  biennials.  Flowers  small, 
bluish-purple  or  white,  in  forked  and  usually  bractless  cymes. 
Calyx  5-parted.  Corolla  funnel-shaped,  the  mouth  closed  by 
prominent  scales,  its  lobes  obtuse.  Stamens  not  projecting. 
Styles  stiff,  persistent.  Nutlets  4,  covered  with  hooked  or 
barbed  bristles,  attached  to  a  thickened,  conical  receptacle. 

1.  C.  officinale,   L.      HOUND'S-TONGUE,    SHEEP-LICE,    DOG-BUR, 
STICK-TIGHTS.      Stem   1-2    ft.    high,   soft-downy,    panicled   above. 
Root-leaves    8-10  in.   long,  long-petioled,  oblong  or  oblong-lanceo- 
late;   stem-leaves   sessile,  linear-oblong   or   lanceolate,  rounded   or 
heart-shaped  at  the  base.     Corolla  £  in.  in  diameter,  reddish-purple. 
Nutlets  %  in-  l°ng>  with  a  thickened  border.      Whole  plant  with  a 
strong  smell  like  that  of  mice.    A  troublesome  weed,  along  roadsides 
and  in  pastures,  introduced  from  Europe. 

2.  C.  virginicum,  L.     WILD  COMFREY.     Perennial.     Stem  stout, 
simple,  erect,  leafless  above,  2-3  ft.  high.     Leaves  oval  or  oblong, 
the    upper  clasping   by  a   heart-shaped  base.      Racemes    bractless. 
Flowers  pale  blue,  on"  short  pedicels,  which  are  recurved  in  fruit. 
Nutlets  not  margined,  separating  and  falling  away  at  maturity.    On 
dry  soil. 

III.     ECHINOSPERMUM,  Lehm. 

Annual  or  biennial  herbs,  grayish,  with  rough  hairs. 
Flowers  small,  blue  or  whitish,  racemed  or  spiked.  Corolla 
salver-shaped,  its  throat  closed  with  5  concave  scales.  Nutlets 


190  FOUNDATIONS  OF   BOTANY 

more  or  less  covered  with  prickles,  which  are  barbed  at  the 
tip,  attached  by  their  sides  to  the  base  of  the  style. 

1.  E.  virginicum,  Lehm.  BEGGAR'S  LICE.  A  coarse  biennial, 
2-4  ft.  high,  the  stem  much  branched  above.  Root-leaves  roundish- 
ovate  or  heart-shaped,  on  slender  petioles ;  stem-leaves  3-4  in.  long, 
pointed  at  both  ends.  Racemes  1-3  in.  long,  terminating  the  slender, 
spreading  branches.  Flowers  small,  bluish-white.  Fruit  forming  a 
troublesome  bur.  Fence-rows  and  thickets. 

IV.    MERTENSIA,  Roth. 

Perennial  herbs.  Leaves  generally  pale,  smooth,  and  entire. 
Calyx  short,  deeply  5-cleft  or  5-parted.  Corolla  somewhat 
trumpet-shaped  or  funnel-shaped,  often  with  5  small  folds  or 
ridges  in  the  throat,  between  the  points  of  insertion  of  the 
stamens.  Style  long  and  slender.  Nutlets  smooth,  or  at 
length  becoming  wrinkled. 

'  1.  M.  virginica,  DC.  LUNGWORT,  BLUEBELLS.  Smooth,  nearly 
erect,  1-11  ft.  high.  Root-leaves  large,  obovate,  or  nearly  so,  and 
petioled;  stem-leaves  smaller,  sessile.  Flowers  clustered.  Corolla 
nearly  trumpet-shaped,  varying  with  age  from  lilac  to  blue  (or  occa- 
sionally white).  Stamens  with  slender  filaments  projecting  beyond 
the  corolla-tube.  Damp,  open  woods  and  banks  of  streams,  some- 
times cultivated. 

V.    MYOSOTIS,  Dill. 

Low,  annual,  biennial,  or  perennial  herbs  ;  stems  branching, 
erect  or  diffuse.  Leaves  alternate,  entire.  Flowers  small, 
blue,  pink,  or  white,  in  elongated,  bractless  racemes.  Calyx 
5-cleft,  the  lobes  erect  or  spreading  in  fruit.  Corolla  salver- 
forni,  5-lobed,  the  tube  as  long  as  the  calyx,  the  throat  with 
5  small  appendages.  Stamens  5,  inserted  in  the  tube  of  the 
corolla,  included.  Ovary  4-parted;  style  slender.  Nutlets 
smooth  or  downy,  elliptical,  compressed.* 

1.  M.  palustris,  Withering.  FORGET-ME-NOT.  Perennial,  from 
slender  rootstocks.  Stems  slender,  downy,  rooting  at  the  nodes, 
6-15  in.  long  ;  leaves  oblong  to  oblong-lanceolate,  obtuse,  narrowed 
to  the  sessile  base,  appressed-downy.  Racemes  many-flowered  ;  pedi- 
cels becoming  elongated  in  fruit.  Lobes  of  the  calyx  shorter  than 
the  tube,  spreading  in  fruit.  Corolla  blue  with  a  yellow  eye ;  nut- 
lets angled,  smooth.  Common  in  gardens  and  often  naturalized.* 


DICOTYLEDONOUS  PLANTS  191 

2.  M.  laxa,  Lehm.  SMALL  FORGET-ME-NOT.  Annual  or  peren- 
nial ;  whole  plant  downy  ;  stem  slender,  weak,  decumbent  and  root- 
ing at  the  base,  1-2  ft.  long.  Lower  leaves  spatulate,  the  upper 
lanceolate.  Racemes  loosely  flowered,  becoming  elongated  in  fruit. 
Pedicels  spreading.  Calyx  rough-hairy,  the  lobes  as  long  as  the 
tube.  Corolla  pale  blue,  with  a  yellow  eye.  Nutlets  -convex  on  all 
sides.  On  low  ground  and  in  brooks  and  ponds.* 


VI.    LITHOSPERMUM,  Tourn. 

Herbs,  with  stout,  usually  reddish  roots.  Flowers  appear- 
ing axillary  and  solitary  or  else  in  leafy-bracted  spikes. 
Corolla  funnel-shaped  or  salver-shaped,  with  or  without  folds 
or  appendages  at  the  mouth  of  the  tube  ;  the  limb  5-cleft,  its 
divisions  rounded.  Stamens  included  in  the  corolla-tube,  the 
anthers  nearly  sessile.  Nutlets  either  smooth  or  wrinkled, 
generally  very  hard  and  bony. 

1.  L.  arvense,  L.     CORN  GROMWELL.     A  rough  weed,  about  1  ft. 
high.     Leaves  narrowly  lanceolate.     Flowers  inconspicuous,  whitish 
in  the  upper  leaf  axils.    Corolla  hardly  extending  beyond  the  calyx, 
without  appendages  in  the  throat.     Nutlets  rough  or  wrinkled  and 
dull.     Sandy  banks  and  roadsides ;  introduced  from  Europe. 

2.  L.  hirtum,  Lehm.     HAIRY  PUCCOON.     Rough-hairy,  perennial, 
1-2  ft.  high.     Corolla  deep  orange-yellow,  with  appendages  in  the 
throat  and  clad  with  wool  within  at  the  bottom ;  flowers  handsome, 
peduncled,  in  a  crowded  cluster.     Dry,  open  pine  woods,  in  sandy  soil. 

3.  L.  canescens,  Lehm.      PUCCOON,  INDIAN  PAINT.      Perennial. 
Clothed  with  soft  hairs,  8-12  in.  high.     Flowers  axillary  and  sessile. 
Corolla  appendaged,  not  woolly  within,  showy,  orange-yellow.    Banks 
and  open  woods. 

VII.    ECHIUM,  Tourn. 

Herbs  or  sometimes  shrubs,  usually  stout,  coarse,  and  hairy. 
Leaves  entire.  •  Flowers  white,  reddish-purple  or  blue,  in 
spiked  or  panicled  racemes.  Calyx  5-parted.  Corolla-tube 
cylindrical .  or  funnel-shaped;  the  throat  dilated;  the  limb 
with  5  unequal  lobes.  Filaments  unequal,  adnate  to  the 
corolla  below,  projecting  from  the  corolla.  Style  thread-like, 
stigma  2-lobed.  Nutlets  4,  ovoid  or  top-shaped,  wrinkled. 

1.  E.  vulgare,  L.     BLUE  THISTLE,  BLUE  WEED,  BLUE  DEVILS, 

Stems  1-3  ft.  high,  more  or  less  erect,  leafy,  covered  with  stinging 


192  FOUNDATIONS   OF  BOTANY 

hairs.  Root-leaves  lanceolate  or  oblong,  petioled,  4-8  in.  long; 
stem-leaves  sessile,  acute,  rounded  at  the  base.  Flowers  showy, 
reddish-purple  in  the  bud,  changing  to  bright  blue.  A  very  trouble- 
some weed,  especially  in  fallow  fields.  Introduced  from  Europe. 


86.    VERBENACE^.     VERBENA  FAMILY. 

Herbs,  shrubs,  or  trees.  Leaves  opposite  or  whorled,  with- 
out stipules.  Flowers  irregular,  in  bracted  cymes.  Calyx 
free  from  the  ovary,  cleft  or  toothed.  Corolla  free  from  the 
ovary,  tubular,  usually  more  or  less  2-lipped.  Stamens  usually 
4,  2  long  and  2  short,  inserted  on  the  corolla-tube.  Ovary 
usually  2-4-celled  (in  Phryma,  1-celled),  with  the  style  spring- 
ing from  its  summit. 

I.    VERBENA,  Tourn. 

Annual  or  perennial  herbs.  Leaves  simple,  opposite,  ser- 
rate or  pinnately  lobed.  Flowers  in  terminal  spikes  which 
become  much  elongated  in  fruit.  Calyx  tubular,  5-ribbed, 
5-toothed.  Corolla  salver-form,  or  funnel-form,  the  tube  often 
curved,  bearded  in  the  throat,  limb  spreading,  5-lobed,  often 
somewhat  2-lipped.  Stamens  4,  2  long  and  2  short,  rarely 
only  2,  included.  Ovary  2-4-celled,  2-4-ovuled ;  style  slen- 
der, 2-lobed.  Fruit  2-4  smooth  or  roughened,  1-seeded  nut- 
lets. [Several  of  the  commonest  species  are  tall,  coarse  herbs 
which  blossom  too  late  for  school  study.]* 

1.  V.  offlcinalis,  L.     EUROPEAN  VERVAIN.     Annual ;  stem  erect, 
slender,  nearly  or  quite  smooth,  branching,   1-3  ft.  high.     Leaves 
ovate  to  obovate  in  outline,  pinnately  lobed  or  divided,  narrowed 
and   entire   toward    the   base,  downy  beneath  ;  petioles  margined. 
Spikes   several,  very  slender;   flowers  small,  purple,  bracts  shorter 
than   the   calyx.      In   fields   and   waste    places;    introduced  from 
Europe.* 

2.  V.  angustifolia,  Michx.     NARROW-LEAVED  VERVAIN.     Peren- 
nial, rough-hairy  ;  stem  simple,  or  branched  below,  from  a  creeping 
base,  1-2  ft.  high.    Leaves  lanceolate  to  spatulate,  obtuse  and  toothed 
at  the  apex,  tapering  to  a  sessile  base.     Spike  peduncled,  slender, 
close-flowered  ;  bracts  about  the  length  of  the  calyx.     Corolla  purple, 
tube  slightly  curved,  £  in.  long.     In  dry,  open  woods.* 


DICOTYLEDONOUS   PLANTS  193 

3.  V.  Aubletia,  L.  VERBENA.  A  slender-stemmed,  somewhat 
reclining  annual,  1  ft.  or  less  in  height.  Leaves  ovate  or  nearly  so, 
wedge-shaped  at  the  base,  lobed  and  toothed  or  3-cleft.  Flowers 
showy,  reddish-purple  or  lilac  (seldom  white),  in  a  peduncled  spike. 
Calyx-teeth  as  long  as  or  longer  than  the  bracts.  Corolla  very 
slightly  bearded  in  the  throat.  In  dry  prairie  soil  and  open  woods, 
also  cultivated.  [Other  somewhat  similar  cultivated  species  are 
from  Brazil.] 

H.     CALLICARPA,  L. 

Shrubs.  Leaves  simple,  petioled,  opposite  or  whorled,  glan- 
dular-dotted. Flowers  in  axillary  cymes.  Calyx  4-toothed  or 
entire.  Corolla  funnel-form,  4-clef t,  regular ;  stamens  4,  equal, 
proj  ecting.  Ovary  4-ovuled ;  style  slender ;  stigma  knobbed. 
Fruit  a  1-4-seeded  berry.* 

1.  C.  americana,  L.     FRENCH  MULBERRY,  MEXICAN  MULBERRY. 

Shrubs,  with  star-shaped,  glandular  or  scurfy  down,  widely  branched, 
3-8  ft.  high.  Leaves  ovate  to  oblong,  acute  at  each  end,  crenate- 
serrate,  rough  above,  downy  beneath,  glandular-dotted ;  petioles  slen- 
der. Cymes  many-flowered,  the  peduncle  as  long  as  the  petiole, 
pedicels  short.  Calyx  cup-shaped,  the  teeth  short.  Corolla  double 
the  length  of  the  calyx,  blue.  Fruit  violet-purple,  very  conspicuous 
in  autumn.  Common  in  fields  and  thickets  S.* 

87.   LABIATJE.    MINT  FAMILY. 

Mostly  herbs,  with  square  stems  and  opposite,  more  or 
less  aromatic  leaves,  without  stipules.  Flowers  generally 
in  cyme-like  axillary  clusters,  which  are  often  grouped  into 
terminal  spikes  or  racemes.  Calyx  tubular,  usually  2-lipped, 
persistent.  Corolla  usually  2-lipped  (Fig.  148).  Stamens  4 
(2  long  and  2  short)  or  only  2.  Ovary  free,  with  4  deep  lobes, 
which  surround  the  base  of  the  style.  Fruit  consisting  of  4 
nutlets,  ripening  inside  the  base  of  the  calyx. 

Stamens  4.  A- 

(a) 'Calyx  2-lipped.  * 

Lips  entire.  Scutellaria,  I. 

Lips  toothed  and  cleft.     Plants  not  aromatic. 

Brunella,  IV. 


194  FOUNDATIONS   OF  BOTANY 

Lips   toothed   and   cleft.      Plants    aromatic.      Leaves 
extremely  small.  Thymus,  IX. 

(b)  Calyx  not  2-lipped,  or  not  much  so. 

Calyx  tubular,  5-10-toothed.     Stamens  not  projecting 
from  tube  of  corolla.  Marrubium,  II. 

Calyx   tubular,  with   5    equal  teeth.     Stamens   under 
upper  lip  of  corolla.  Nepeta,  III. 

Calyx  tubular,  bell-shaped,  with  5    awl-shaped   teeth. 
Stamens  not  turned  down  after  maturing. 

Lamiurn,  V. 

Calyx  top-shaped,  with  spreading  spiny  teeth. 

Leonurus,  VI. 

Calyx  as  in  No.  5.     Stamens  turned  down  after  ma- 
turing. Stachys,  VII. 

B. 

Stamens'  2.  .  Salvia,  VIII. 

I.    SCUTELLARIA,  L. 

Mostly  slender  herbs,  not  aromatic.  Flowers  solitary  or  in 
pairs,  axillary  or  in  terminal  spikes  or  racemes.  Calyx  bell- 
shaped,  2-lipped,  the  upper  part  swollen  into  a  helmet-shaped 
pouch ;  mouth  of  the  calyx  closed  after  flowering.  Corolla- 
tube  long,  naked  inside.  Stamens  4,  the  anthers  meeting  in 
pairs,  hairy-fringed.  Style  with  a  very  short  upper  lobe. 
[The  species  here  described  are  not  the  commonest  ones,  but 
most  of  the  others  grow  in  damp  soil  and  bloom  later.] 

1.  S.  serrata,  Andrews.     SKULLCAP.     Stem  not  much  branched, 
1-3  ft.  high.     Stem-leaves  serrate,  taper-pointed  at  both  ends,  ovate 
or  nearly  so.     Racemes  single,  loose.     Calyx  rather  hairy.     Corolla 
1  in.  long,  the  lips  of  equal  length.     Woods. 

2.  S.  pilosa,  Michx.    HAIRY  SKULLCAP.    Stem  more  or  less  hairy, 
not  much  if  at  all  branched,  1-3  ft.  high.     Leaves  a  few  distant 
pairs,    diamond-ovate,    oblong-ovate,    or    roundish-ovate,    scalloped, 
obtuse,  the  lower  heart-shaped  or  nearly  truncate  at  the  base,  with 
long   petioles.     Racemes   short,    few-flowered.     Corolla  £  in.  long, 


DICOTYLEDONOUS  PLANTS  195 

tube  whitish,  lips  blue,  the  lower  one  rather  shorter.     Open  wood- 
lands and  dry  soil. 

3.  S.  integrifolia,  L.  LARGE-FLOWERED  SKULLCAP.  Stem  cov- 
ered with  fine,  grayish  down,  usually  unbranched,  1-2  ft.  high. 
Leaves  lance-oblong  or  nearly  linear,  mostly  entire,  obtuse,  with  very 
short  petioles.  Corolla  1  in.  long,  tube  pale,  lips  large  and  spread- 
ing, blue.  Dry  ground. 

II.    MARRUBIUM,  Tourn. 

Perennial,  downy,  or  woolly  herbs.  Whorls  of  flowers  axil- 
lary ;  flowers  small;  bracts  leaf -like.  Calyx  tubular,  5-10- 
toothed,  teeth  somewhat  spiny.  Corolla  short ;  upper  lip 
erect,  lower  spreading,  3-cleft,  the  middle  lobe  broadest. 
Stamens  4,  not  projecting.  Lobes  of  the  stigma  short  and 
blunt. 

1.  M.  vulgare,  L.  HOREHOUND.  Stems  somewhat  reclining, 
stout,  branching,  leafy,  1-1£  ft.  high.  Leaves  broadly  ovate,  heart- 
shaped  or  wedge-shaped  at  the  base,  scalloped,  leathery  and  wrinkled. 
Whorls  of  flowers  dense.  Calyx-teeth  hooked  at  the  tip.  Corolla  £ 
in.  long,  white.  Cultivated  from  Europe  as  an  herb  (used  in  prepa- 
ration of  horehound  candy)  and  somewhat  naturalized. 


m.    NEPETA,  L. 

Erect  or  prostrate  herbs.  Whorls  of  flowers  axillary  or  ter- 
minal; flowers  blue  or  white.  Calyx  tubular,  15-ribbed, 
5-toothed.  Corolla-tube  slender  below,  dilated  at  the  throat, 
naked ;  upper  lip  notched  or  2-cleft ;  lower  lip  3-cleft,  middle 
lobe  large.  Stamens  4,  ascending  under  the  upper  lip,  the 
upper  pair  longer.  Lobes  of  the  stigma  awl-shaped. 

1.  N.  Cataria,  L.     CATNIP.     Stem  grayish,  downy,  2-3  ft.  high, 
branched,  very  leafy.     Leaves  large,  ovate-heart-shaped,  deeply  scal- 
loped, serrate,  white  and  downy  beneath.     Corolla  about  £  in.  long, 
whitish  with   purple  dots.      Introduced  from  Europe ;    a  common 
weed  about  dooryards. 

2.  N.  Glechoma,  Benth.     GROUND  IVY,  GILL-OVER-T HE-GROUND, 
CREEPING  CHARLEY,    CROW-VICTUALVS,    ROBIN-RUNAWAY.     Creep- 
ing.    Leaves  roundish,  kidney-shaped,  and  crenate.     Corolla  bluish- 
purple,  three  times  as  long  as  the  calyx.     Introduced  from  Europe, 
common  in  damp  places  about  houses  and  gardens. 


196  FOUNDATIONS   OF   BOTANY 


IV.    BRUNELLA,  Tourn. 

Perennials,  with  stems  simple  or  nearly  so,  and  sessile, 
3-flowered  flower-clusters  in  the  axils  of  kidney-shaped 
bracts,  the  whole  forming  a  spike  or  head.  Calyx  tubular- 
bell-shaped,  somewhat  10-ribbed,  upper  lip  broad,  3-toothed, 
the  teeth  short,  lower  lip  with  2  longer  teeth.  Upper  lip  of 
the  corolla  upright,  arched,  and  entire,  the  lower  spreading, 
reflexed,  fringed,  and  3-cleft.  Stamens  4,  reaching  up  under 
the  upper  lip,  with  the  tips  of  the  filaments  2-toothed,  only 
one  tooth  anther-bearing. 

1.  B.  vulgaris,  L.  SELF-HEAL,  HEAL-ALL,  CARPENTER-WEED. 
Leaves  with  petioles,  ovate-oblong,  either  entire  or  toothed,  often 
somewhat  hairy.  Corolla  usually  blue  or  bluish,  somewhat  longer 
than  the  brown-purple  calyx.  Open  woods  and  fields  everywhere. 


V.    LAMIUM,  L. 

Annual  or  perennial  hairy  herbs.  Calyx  tubular-bell- 
shaped,  5-veined,  with  5  awl-pointed  teeth  of  nearly  equal 
length.  Corolla  with  dilated  throat,  upper  lip  arched,  middle 
lobe  of  the  lower  lip  notched,  the  lateral  lobes  small,  close  to 
the  throat  of  the  corolla.  Stamens  4,  rising  beneath  the 
upper  lip. 

1.  L.  amplexicaule,  L.    HEN-BIT,  DEAD  NETTLE.     An  annual  or 
biennial  weed.     Leaves  roundish,  deeply  scalloped,  the  lower  ones 
petioled,  the  upper  sessile  and  clasping.     Corolla  sometimes  f  in. 
long,  downy,  rose-colored  or  purplish.       Introduced  from  Europe ; 
not  uncommon  about  gardens  and  dooryards. 

2.  L.  purpureum,  L.     Stem  6-18  in.  high,  silky-hairy  or  nearly 
smooth,  reclining  below,  branched  from  the  base.     Leaves  long-peti- 
oled,    obtuse,    heart-shaped,    scalloped.      Whorls  of  flowers  mostly 
terminal,   crowded.      Corolla  £-|  in.  long,  purple   (rarely  white). 
Introduced  from  Europe. 

VI.    LEONURUS,  L. 

Erect  herbs.  Leaves  lobed.  Whorls  of  flowers  axillary, 
densely  flowered,  scattered  j  bractlets  awl-shaped ;  flowers 
small,  pink  or  white.  Calyx  5-nerved,  top-shaped,  with  5 
rather  spiny,  spreading  teeth.  Corolla  with  upper  lip  erect 


DICOTYLEDONOUS  PLANTS  197 

and  entire,  lower  3-cleft.    Stamens  4 ;  anthers  joined  in  pairs. 
Nutlets  with.  3  projecting  angles,  their  sides  channeled. 

1.  L.  cardiaca,  L.  MOTHERWORT.  Stem  2-4  ft.  high,  prominently 
angled,  stiff,  stout,  upright,  very  leafy.  Leaves  palmately  lobed  or 
cleft ;  radical  ones  long-petioled ;  lower  stem-leaves  many-cleft,  the 
upper  ones  3-cleft,  prominently  nerved,  the  divisions  acute.  Corolla 
£  in.  long,  pale  rose-color,  the  upper  lip  and  outside  of  the  tube 
densely  soft-bearded.  Common  about  dooryards  and  fence-rows. 
Introduced  from  Europe. 


VII.    STACHYS,  Tourn. 

Herbs,  rarely  shrubs.  Leaves  scalloped  or  serrate.  Whorls 
of  flowers  2  or  more  flowered,  usually  in  terminal  racemes. 
Calyx  nearly  bell-shaped,  5-toothed.  Corolla-tube  cylindrical, 
usually  with  a  ring  of  hairs  inside,  not  dilated  at  the  throat ; 
upper  lip  erect  or  spreading;  lower  spreading,  3-lobed,  the 
middle  lobe  largest.  Stamens  4,  the  2  lower  longest. 

1.  S.  palustris,  L.     Perennial;  stem  erect,  4-angled,  2-3  ft.  high, 
hairy,  especially  on  the  angles,  with  projecting  or  reflexed  hairs, 
leafy.      Stem-leaves    short-petioled   or   sessile,    ovate-lanceolate    or 
oblong-lanceolate,  scalloped-serrate,  coarsely  or  finely  downy,  round- 
ish at  the  base,  rather  obtuse  at  the  tip.     Calyx  bristly,  the  lance- 
awl-shaped  teeth  rather  spiny.    Upper  lip  of  the  corolla  downy.    In 
wet  soil,  especially  N. 

2.  S.  aspera,  Michx.    Taller  than  No.  1 ;  angles  of  the  stem  covered 
with  stiff  reflexed  bristles,  but  the  sides  often  smooth.     Leaves  ser- 
rate, nearly  all  with  distinct  petioles.    Calyx  usually  smooth.    Corolla 
smooth  throughout.     Damp  thickets  and  along  streams. 


Vm.     SALVIA,  L. 

Annual,  biennial,  or  perennial  herbs,  or  sometimes  shrubby. 
Flowers  in  spikes,  racemes,  or  panicles,  usually  showy.  Calyx 
tubular  or  bell  shaped,  not  bearded  in  the  throat,  2-lipped, 
the  upper  lip  entire  or  3-toothed,  the  lower  2-cleft.  Corolla 
2-lipped,  the  upper  lip  entire  or  notched,  the  lower  spread- 
ing, 3-lobed,  with  the  middle  lobe  longer.  Stamens  2,  short, 
anthers  2-celled,  the  upper  cell  fertile,  the  lower  imperfect. 
Style  2-cleft.  Nutlets  smooth.* 


198  FOUNDATIONS   OF   BOTANY 

1.  S.  lyrata,  L.     LYRE-LEAVED  SALVIA,     Biennial  or  perennial; 
stem  erect,   sparingly  branched  above,  rough-hairy,   1-2    ft.  high. 
Leaves   mostly   basal,   spreading,   lyrate-pinnatifid,   usually   purple, 
stem-leaves  small,  sessile  or  short-petioled.     Racemes  many-flowered, 
whorls  about  6-flowered.     Calyx-teeth  short  on  the  upper  lip,  long 
and  awl-shaped  on  the  lower.     Corolla  blue   or  purple,  the  tube 
about  1  in.  long,  dilated  upward.     On  dry  soil.* 

2.  S.  officinalis,  L.    GARDEN  SAGE.    Stem  shrubby,  slender,  much 
branched  below,  1  ft.  high.     Leaves  grayish-green,  lance-oblong,  cre- 
nate,  wrinkled.     Flowers  in  terminal  spikes,  whorls  several-flowered. 
Corolla  blue,  upper  lip  strongly  arched,  about  equaling  the  lower. 
Introduced  from  Europe  and  a  common  garden  herb.* 

IX.    THYMUS,  L. 

Small,  much-branched  shrubs,  very  aromatic.  Leaves  small, 
entire,  margins  often  rolled  under.  Whorls  of  flowers  few- 
flowered,  in  loose  or  close  spikes  ;  bracts  very  small ;  flowers 
usually  purple.  Calyx  ovoid,  2-lipped,  upper  lip  3-toothed, 
lower  2-cleft,  woolly  in  the  throat.  Corolla  slightly  2-lipped. 
Stamens  4,  usually  projecting  from  the  flower,  straight,  lower 
pair  longer. 

1.  T.  Serpyllum,  L.     CREEPING  THYME.     Smooth  or  hairy,  stem 
prostrate,  the  flowering  branches  somewhat  ascending.     Leaves  ^—  \ 
in.  long,  flat,  ovate  or  obovate-lanceolate,  obtuse.     Flowers  crowded 
in  spikes  at  the  end  of  the  branches.     Corolla  rose-purple,  3— f  in. 
long.     Becoming  introduced  from  Europe. 

2.  T.  vulgaris,  L.     GARDEN  THYME.     More  erect  than  No.  1. 
Leaves  somewhat  curled  under  at  the  edges.    Flower-clusters  shorter 
and  not  all  terminal.     Corolla  pale  purple.    Cultivated  from  Europe 
as  an  herb. 

88.    SOLANACE^.     NIGHTSHADE  FAMILY. 

Mostly  tropical  herbs  or  shrubs  (rarely  trees).  Leaves 
usually  alternate,  without  stipules.  Flowers  regular,  borne 
on  bractless  pedicels  at  or  above  the  leaf  axils,  or  in  cymes. 
Calyx  free  from  the  ovary,  5-cleft,  usually  persistent.  Corolla 
hypogynous,  wheel-shaped,  bell-shaped,  or  salver-shaped,  5- 
lobed.  Stamens  5,  short,  inserted  on  the  corolla-tube.  Ovary 
2-celled  or  imperfectly  4-celled ;  style  simple ;  stigma  simple 
or  lobed.  Fruit  a  many-seeded  capsule  or  berry. 


DICOTYLEDONOUS   PLANTS  199 


I.    LYCIUM,  L. 

Shrubs  or  woody  vines,  often  spiny.  Leaves  entire,  alter- 
nate, often  fascicled.  Flowers  solitary  or  clustered,  terminal 
or  axillary.  Calyx  persistent,  4-5-lobed  or  toothed,  not  en- 
larged in  fruit.  Corolla  funnel-form  or  bell-shaped,  the  limb 
4-5-lobed,  the  lobes  obtuse.  Stamens  4-5,  projecting.  Ovary 
2-celled ;  style  single ;  stigma  obtuse.  Fruit  a  many-seeded 
berry.1* 

1.  L.  vulgare,  Dunal.  MATRIMONY  VINE.  Stem  slender,  branch- 
ing, twining  or  trailing,  6-15  ft.  long;  branches  angled,  spiny. 
Leaves  elliptical,  smooth,  entire,  sessile,  or  short-petioled.  Flowers 
solitary  or  few  in  the  axils ;  peduncles  long  and  slender.  Corolla 
spreading,  greenish-purple,  ^-£  in.  wide.  Berry  oval,  orange-red. 
Introduced  from  Africa,  and  often  planted  for  covering  trellises.* 


II.    SOLANUM,  Toura. 

Herbs  or  shrubs ;  stems  often  prickly,  sometimes  climbing. 
Leaves  alternate,  often  nearly  or  quite  opposite.  Flowers 
clustered,  the  peduncles  often  opposite  or  above  the  axils. 
Calyx  spreading,  5-toothed  or  5-cleft,  persistent.  Corolla 
wheel-shaped,  5-lobed.  Stamens  5,  projecting,  the  filaments 
very  short,  the  anthers  long  and  meeting  about  the  style. 
Ovary  2-celled ;  style  slender.  Fruit  a  many-seeded,  juicy 
berry.* 

1.  S.  Dulcamara,  L.     BITTERSWEET.     Perennial.     Stems  rather 
shrubby,  long,  and  climbing.    Leaves  heart-shaped,  or  some  of  them 
with  irregular  lobes,  or  ear-like  leaflets  at  the  base.     Flowers  blue 
or  purple,  somewhat  cymose.     Berries  showy,  of  many  shades  of 
orange  and  red  in  the  same  cluster,  according  to  their  maturity. 

2.  S.    nigrum,    L.      NIGHTSHADE.      Annual;    stem   smooth,    or 
downy  with  simple  hairs,  erect,  diffusely  branched ;  branches  wing- 
angled,  1-3  ft.  high.     Leaves  ovate,  irregularly  toothed  or  entire, 
somewhat  inequilateral,  petioled.     Flowers  in  lateral,  peduncled  um- 
bels, small,  white,  drooping.     Calyx-lobes    obtuse;    corolla  £-£  in. 
wide;  filaments  downy;  berries  globose,  smooth,  black  when  ripe. 
Common  in  cultivated  fields  and  waste  places.* 

3.  S.  carolinense,  L.     HORSE   NETTLE.     Perennial;    stem  erect, 
branched,  downy  with  star-shaped  hairs,  armed  with  straight,  yellow 
prickles,  1-3  ft.  high.    Leaves  ovate-oblong,  deeply  toothed  or  lobed, 


200  FOUNDATIONS   OF   BOTANY 

acute  at  the  apex,  abruptly  contracted  to  the  short  petiole,  prickly 
on  the  veins.  Racemes  lateral,  few-flowered ;  pedicels  recurved  in 
fruit.  Calyx-lobes  taper-pointed.  Corolla  deeply  angular-lobed, 
blue  or  white ;  berry  globose,  smooth,  yellow.  A  common  weed.* 

4.  S.  rostratum,  Dunal.     SAND  BUR,  BUFFALO   BUR.     Annual; 
the  whole  plant  beset  with  yellow  prickles ;   stem   erect,  diff usely 
branched,  1-2  ft.  high.      Leaves  broadly  oval  or  ovate  in  outline, 
deeply  pinnately  lobed  or  parted,  petioled,  downy,  with  star-shaped 
hairs.     Racemes  few-flowered ;  pedicels  erect  in  fruit.     Calyx  very 
prickly,  becoming  enlarged  and  enclosing  the  fruit.     Corolla  bright 
yellow,  5-angled,  about   1   in.  broad.     Introduced  from  the  West, 
and  becoming  a  troublesome  weed  in  some  places.* 

5.  S.   tuberosum,   L.     IRISH   POTATO.     Annual;    stem   diffusely 
branched,  downy,  underground  branches  numerous  and  tuber-bearing. 
Leaves  irregularly  pinnatifid  and  divided.     Flowers  in  cymose  clus- 
ters, white   or    purple,    with   prominent   yellow   anthers ;    pedicels 
jointed.     Corolla  5-angled,  |-1  in.  broad.     Fruit  a  globose,  greenish- 
yellow,  many-seeded  berry,  about  £  in.  in  diameter.    Cultivated  from 
Chili* 

HI.    LYCOPERSICUM,  Tourn. 

Annual  ;  stem  diffusely  branched.  Leaves  pinnately  divided. 
Flowers  in  raceme-like  clusters  on  peduncles  opposite  the 
leaves.  Calyx  5-many-parted,  persistent.  Corolla  wheel- 
shaped,  5-6-parted.  Stamens  5-6,  inserted  in  the  short  tube 
of  the  corolla,  filaments  short,  anthers  elongated.  Ovary 
2-several-celled,  style  and  stigma  simple.  Fruit  a  many- 
seeded  berry.* 

1.  L.  esculentum,  Mill.  TOMATO.  Stem  diffusely  branched,  at 
length  leaning  over,  furrowed  and  angled  below,  sticky-hairy,  3-5 
ft.  long.  Leaves  irregularly  lobed  and  pinnatifid,  petioled.  Calyx- 
lobes  linear,  about  as  long  as  the  yellow  corolla.  Fruit  (in  the  wild 
state)  globose  or  ovoid,  red  or  yellow,  £- £  in.  in  diameter,  but  greatly 
enlarged  in  cultivation.  Common  in  cultivation  from  tropical 
America.* 

IV.     DATURA,  L. 

Annual  or  perennial,  strong-scented  herbs ;  stems  tall  and 
branching.  Leaves  petioled,  entire  or  lobed.  Flowers  large,  soli- 
tary in  the  forks  of  the  branches.  Calyx  tubular,  5-toothed 
or  lobed,  the  upper  part  deciduous  and  the  lower  persistent. 
Corolla  funnel-form,  5-angled.  Stamens  5,  inserted  in  the 


DICOTYLEDONOUS   PLANTS  201 

corolla-tube.  Ovary  2-celled  or  imperfectly  4-celled  ;  style 
filiform  ;  stigma  2-lobed.  Fruit  a  spiny,  4-valved,  many-seeded 
capsule.* 

1.  D.  Stramonium,  L.     JIMSON-WEED.     Annual ;    stem    smooth, 
green,  stout,  forking  above,  1—4  ft.  high.     Leaves  ovate  to  oblong- 
ovate,  acute   at   the  apex,  narrowed  at   the  base,  sinuate-toothed, 
petioled.    Calyx  5-angled.    Corolla  white,  about  4  in.  long.    Capsule 
ovoid,  erect,  2  in.  long.     A  common  weed  ;  poisonous.     Introduced 
from  Asia.* 

2.  D.  Tatula,  L.     Taller,  with  a   purple   stem.     Flowers  rather 
later  than  No.  1 ;  corolla  violet-tinged. 


V.    PETUNIA,  Juss. 

Herbs ;  leaves  alternate  and  entire.  Divisions  of  the  calyx 
oblong-spatulate.  Corolla  showy,  spreading  funnel-shaped, 
not  perfectly  regular.  Stamens  5,  somewhat  unequal  in 
length,  inserted  in  the  middle  of  the  corolla-tube  and  not 
projecting  beyond  it.  Capsule  2-celled,  containing  many  very 
small  seeds. 

1.  P.  violacea,  Lindl.     COMMON  PETUNIA.     Stems  rather  weak 
and  reclining.     Leaves  covered  with  clammy  down.     Corolla  vary- 
ing from  pale  pink  to  bright  purplish-red,  often  variegated,  with 
a  broad,  inflated  tube,  which  is  hardly  twice  as  long  as  the  calyx. 
Cultivated  annual  from  South  America. 

2.  P.  nyctaginiflora,  Juss.     WHITE  PETUNIA.     Leaves  somewhat 
petioled.     Tube  of  corolla  long  and  slender.    Flowers  white.     Culti- 
vated from  South  America.     This  and  the  preceding  species  much 
mixed  by  hybridization. 


89.   SCROPHULARIACEJE.     FIGWORT  FAMILY. 

Mostly  herbs,  with  irregular  flowers.  Calyx  free  from  the 
ovary  and  persistent.  Corolla  2-lipped  or  otherwise  more  or 
less  irregular.  Stamens  usually  2  long  and  2  short,  or  only 
2  in  all,  inserted  on  the  corolla-tube,  often  1  or  3  of  them 
imperfectly  developed.  Pistil  consisting  of  a  2-celled  and 
usually  many-ovuled  ovary,  with  a  single  style  and  an  entire 
or  2-lobed  stigma. 


202  FOUNDATIONS   OF  BOTANY 

Corolla  wheel-shaped,  stamens  5.  Verbascum,  I. 

Corolla  wheel-shaped  or  salver-shaped,  nearly  regular,  stamens  2. 

Veronica,  VI. 

Corolla  2-lipped,  the  mouth  closed  by  a  palate,  tubular  below,  a 

spur  at  the  base.  Linaria,  II. 

Corolla  2-lipped,  the  mouth  closed  by  a  palate,  tubular  below,  a 

short,  broad  pouch  at  the  base.  Antirrhinum,  III. 

Corolla  decidedly  2-lipped. 

Stamens  with  anthers  2.  Gratiola,  V. 

Stamens  4,  with  a  fifth  antherless  filament.        Pentstemon,  IV. 
Stamens  4,  the  anther-cells  unequal.  Castilleia,  VII. 

Stamens  4,  the  anther-cells  equal.  Pedicularis,  VIII. 

I.     VERBASCUM,  L. 

Biennial ;  stem  tall,  erect.  Leaves  alternate.  Flowers  in 
spikes,  racemes  or  panicles.  Calyx  deeply  5-cleft.  Corolla 
wheel-shaped,  5-lobed,  the  lobes  nearly  equal.  Stamens  5, 
unequal,  declined,  some  or  all  of  the  filaments  bearded. 
Style  flattened  at  the  apex.  Fruit  a  globose  capsule  ;  seeds 
roughened.* 

1.  V.  Blattaria,  L.  MOTH  MULLEIN.  Stem  erect,  slender,  sim- 
ple or  sparingly  branched,  smooth  below,  downy  above,  2-4  ft.  high. 
Leaves  oblong  to  lanceolate,  acute  at  the  apex,  obtuse  or  truncate  at 
the  base,  dentate  to  pinnately  lobed,  the  lower  petioled,  the  upper 
sessile  and  clasping.  Raceme  long  and  loose,  glandular-downy, 
pedicels  bracted.  Corolla  white  or  yellow,  marked  with  brown  on 
the  back,  about  1  in.  wide.  Filaments  all  bearded  with  purple 
hairs.  Capsule  longer  than  the  calyx.  Common  in  fields  and  waste 
places  ;  introduced  from  EuTope.* 

n.     LINARIA,  Tourn. 

Herbs,  rarely  shrubby.  Lower  leaves  opposite,  whorled  or 
alternate.  Flowers  in  bracted  racemes  or  spikes  or  axillary 
and  solitary.  Calyx  5-parted.  Corolla  2-lipped,  the  tube 
spurred.  Stamens  4,  with  sometimes  a  rudiment  of  a  fifth. 
Stigma  notched  or  2-lobed.  Capsule  ovoid  or  globose ;  cells 
nearly  equal. 


DICOTYLEDONOUS   PLANTS  203 

1.  L.   vulgaris,   Miller.     BUTTER-AND-EGGS,   JACOB'S    LADDER, 
WILD  FLAX.     A  perennial,  erect,  smooth  herb,  with  a  bloom,  stem 
1-2    ft.    high.     Leaves    linear   or   lanceolate,    1-3    in.    long,    often 
whorled.     Racemes  densely  flowered.     Sepals  shorter  than  the  spur. 
Corolla  yellow,   f-1  in.  long  ;  spur  parallel  to  and  as  long  as  the 
tube  ;  throat  closed  by  a  palate-like  fold.    Common  in  dry  fields  and 
pastures  and  along  roadsides  ;  introduced  from  Europe. 

2.  L.    canadensis,    Dumont.      TOAD-FLAX.     Biennial ;    flowering 
stems  erect,  slender,  rarely  branched,  smooth,  1-2  ft.  high,  sterile 
stems   prostrate,  with   opposite   or  whorled   leaves,   2-6    in.   long. 
Leaves   linear,  entire,  sessile.      Racemes   erect,    slender ;    pedicels 
erect,  as  long  as  the  calyx.     Corolla  small,  blue  and  white,  the  spur 
thread-like,  curved,  longer  than  the  pedicels.     Capsule  2-valved,  the 
valves  3-toothed.     On  dry  or  cultivated  ground  E. 

III.    ANTIRRHINUM,  Tourn. 

Annual  or  perennial  herbs.  Leaves  entire,  rarely  lobed, 
the  lower  ones  opposite,  the  upper  alternate.  Flowers  axillary 
and  solitary  or  racemed  and  bracted.  Calyx  5-parted. 
Corolla  2-lipped.  The  tube  with  a  sac,  the  broad  bearded 
palate  closing  the  throat.  Stamens  4»  Stigma  with  2  short 
lobes.  Capsule  2-celled,  the  upper  cell  opening  by  1  pore, 
the  lower  by  2. 

1.  A.  majus,  L.  SNAPDRAGON.  Perennial;  stem  erect,  smooth 
below,  glandular-downy  above,  1-2  ft.  high.  Leaves  linear  to 
oblong-lanceolate,  entire,  smooth,  sometimes  fleshy,  sessile  or  short- 
petioled.  Flowers  in  a  terminal  raceme  ;  pedicels  short,  stout, 
erect  in  fruit.  Corolla  1^-2  in.  long,  of  many  colors.  Capsule 
oblique,  the  persistent  base  of  the  style  bent  forward.  Common  in 
gardens,  cultivated  from  Europe,  and  often  escaped.* 

IV.     PENTSTEMON,  Mitchell. 

Perennials,  the  stems  branching  from  the  base,  unbranched 
above.  Leaves  opposite.  Flowers  usually  showy  in  a  termi- 
nal panicle.  Calyx  of  5  nearly  distinct  sepals.  Corolla 
tubular,  the  tube  wide  above  and  narrowed  below ;  2-lipped. 
Stamens  4,  2  long  and  2  short,  with  a  fifth  antherless  filament 
as  long  as  the  others,  its  upper  half  bearded.  Capsule  ovoid, 
acute. 

1.  P.  pubescens,  Solander.  Stem  somewhat  sticky-downy,  1-2 
ft.  high.  Leaves  varying  from  oblong  to  lanceolate,  2-4  in,  long, 


204  FOUNDATIONS  OF   BOTANY 

usually  with  small  teeth.  Flower-cluster  narrow.  Corolla  dingy 
violet,  purplish,  or  whitish,  the  tube  not  much  widened  above,  its 
throat  nearly  closed  by  a  hairy  palate.  Sterile  filament  much 
bearded.  Dry  hillsides  or  stony  ground. 

2.  P.    laevigatus,    Solander.      Stem   usually   smooth    except   the 
flower-cluster,  2-4   ft.    high.     Leaves   shining,    those   of   the   stem 
ovate-lanceolate  or  broadly  lanceolate,  2-5  in.  long,  with  a  somewhat 
heart-shaped  clasping  base.     Flower-cluster  broader  than  in  Xo.  1. 
Corolla  white  or  oftener  purplish,  suddenly  widened  above,  the  throat 
not  closed.     Sterile  filament  slightly  bearded  toward  the  top.     In 
rich  soil. 

3.  P.  barbatus,  Nutt.     Stems  slender  and  rod-like,  3-4  ft.  high. 
Leaves  lanceolate,  entire.     Flower-cluster  long  and  loosely  flowered. 
Flowers  showy,  drooping.     Corolla-tube  slender,  scarlet,  somewhat 
bearded  in  the  throat.     Sterile  filament  beardless.     Cultivated  from 
Mexico. 

V.    GRATIOLA,  L. 

Low  herbs  growing  in  wet  or  damp  ground.  Leaves  oppo- 
site, sessile.  Flowers  axillary  and  solitary,  peduncled.  Calyx 
5-parted.  usually  with  2  braetlets  at  the  base.  Corolla  some- 
what 2-lipped.  Perfect  stamens  2.  Stigma  enlarged  or 
2-lipped.  Pod  4-valved,  many-seeded. 

1.  G.  virginiana,  L.  Stem  cylindrical,  4-10  in.  long,  branching 
from  the  base.  Leaves  f-H  in.  long,  varying  from  lance-oblong  to 
spatulate.  Corolla  pale  yellow,  tinged  with  red.  Common  in  muddy 
soil,  along  brooksides,  etc. 


VT»    VERONICA,  Tourn. 

Herbs  or  shrubs.  Lower  leaves  or  all  the  leaves  opposite. 
rarely  whorled.  Flowers  in  axillary  or  terminal  racemes. 
rarely  solitary.  Calyx  usually  4-parted.  Corolla  wheel- 
shaped  or  somewhat  bell-shaped;  limb  usually  4-cleft,  spread- 
ing, the  side  lobes  commonly  narrower.  Stamens  2,  inserted 
on  the  corolla-tube  at  the  sides  of  the  upper  lobe,  projecting. 
Stigma  somewhat  knobbed.  Capsule  generally  flattened,  often 
notched  at  the  apex,  2-celled,  few-m any-seeded. 

1.  V.  americana,  Schweinitz.  BROOKLIME.  A  perennial  smooth 
herb,  somewhat  prostrate  below,  but  the  upper  parts  of  the  stem 
erect,  8-15  in.  high.  Leaves  1-2  in.  long,  lance-ovate  or  oblong, 


DICOTYLEDONOUS  PLANTS  205 

serrate,  short-petioled.  Racemes  2-4  in.  long,  axillary  and  opposite. 
Corolla  wheel-shaped,  blue.  Capsule  swollen,  roundish.  Muddy 
soil  about  springs  and  brooks. 

2.  V.   officinalis,  L.       COMMON     SPEEDWELL,     GYPSY     WEED. 
Perennial.     Roughish-downy,  with   the   prostrate   stems   spreading 
and  rooting.     Leaves   wedge-oblong   or   nearly  so,  obtuse,  serrate, 
somewhat  petioled.     Racemes  dense,  of  many  pale  bluish  flowers. 
Capsule   rather  large,   inversely  heart-shaped  arid  somewhat  trian- 
gular.    Dry  hillsides,  open  woods  and  fields. 

3.  V.  serpyllifolia,  L.     THYME-LEAVED  SPEEDWELL.    Perennial. 
Smooth  or  nearly  so ;  branching  and  creeping  below,  but  with  nearly 
simple  ascending  shoots,  2-4  in.  high.     Leaves  slightly  crenate,  the 
lowest  ones  petioled  and  roundish,  those  farther  up  ovate  or  oblong, 
the  uppermost  ones  mere  bracts.    Raceme  loosely  flowered.     Corolla 
nearly  white  or  pale  blue,  beautifully  striped  with  darker  lines ;  cap- 
sule inversely  heart-shaped,  its  width  greater  than  its  length.    Damp 
grassy  ground  ;  a  common  weed  in  lawns. 

4.  V.  peregrina,  L.     PURSLANE  SPEEDWELL.     A  homely,  rather 
fleshy,  somewhat  erect-branched  annual  weed,  4-9  in.  high.     Lowest 
leaves  petioled,  oblong,  somewhat  toothed,  those  above  them  sessile, 
the  uppermost   ones  broadly  linear  and  entire.     Flowers  solitary, 
inconspicuous,  whitish,  barely  pediceled,  appearing  to  spring  from 
the  axils  of  the  small  floral  leaves.     Corolla  shorter  than  the  calyx. 
Roundish,  barely  notched,  many-seeded.     Common  in  damp  ground, 
in  fields  and  gardens. 

VII.    CASTILLEIA,  Mutis. 

Herbs  parasitic  on  the  roots  of  other  plants.  Leaves  alter- 
nate ;  the  floral  ones  usually  colored  at  the  tip  and  more  showy 
than  the  flowers.  Flowers  yellow  or  purplish  in  terminal 
leafy  spikes.  Calyx  tubular,  flattened,  2-4-cleft.  Corolla-tube 
included  within  the  calyx;  upper  lip  of  the  corolla  very  long, 
linear,  arched,  and  enclosing  the  stamens,  2  of  which  are  long 
and  2  short.  Ovary  many-ovuled. 

1.  C.  coccinea,  Sprengel.  SCARLET  PAINTED  CUP,  PAINT-BRUSH, 
INDIAN  PINK,  PRAIRIE  FIRE,  WICKAKEE.  A  hairy,  simple-stemmed 
herb.  Annual  or  biennial.  Root-leaves  clustered  obovate  or  oblong. 
Stem-leaves  cut ;  floral  leaves  3-5  cleft  and  bright  scarlet  (occasion- 
ally yellow)  toward  the  tips,  as  though  dipped  in  a  scarlet  dye.  Calyx 
nearly  as  long  as  th#  pale  yellow  corolla,  2-cleft.  The  spikes  are 
often  very  broad,  making  this  one  of  the  most  conspicuous  of  our 
native  flowers.  Damp,  sandy  ground,  or  on  bluffs  near  streams; 
sometimes  in  marshes. 


206  FOUNDATIONS   OF  BOTANY 


VIII.    PEDICULARIS,  Tourn. 

Perennial  herbs,  with  the  lower  leaves  pinnately  cut  and 
the  floral  ones  reduced  to  bracts.  Flowers  spiked.  Corolla 
markedly  2-lipped;  the  upper  lip  much  flattened  laterally  and 
arched,  the  lower  lip  spreading,  3-lobed.  Stamens  4,  beneath 
the  upper  lip.  Capsule  2-celled,  tipped  with  an  abrupt  point, 
several-seeded. 

1.  P.  canadensis,  L.  COMMON  LOUSEWORT.  Hairy,  with  clus- 
tered simple  stems,  1  ft.  high  or  less.  Leaves  petioled,  the  lower- 
most ones  pinnately  parted,  the  others  somewhat  pinnately  cut ;  spike 
short,  closely  flowered  and  leafy-bracted ;  calyx  split  down  the  front ; 
corolla  greenish-yellow  and  purplish,  with  its  upper  lip  hood-like, 
curved  under,  and  with  2  awl-like  teeth  near  the  end ;  capsule  flat, 
broadly  sword-shaped.  Knolls  and  openings  among  thickets. 


90.    BIGNONIACE^E.     BIGNONIA  FAMILY. 

Trees  or  shrubs,  often  twining  or  climbing,  rarely  herbs. 
Leaves  usually  opposite,  without  stipules.  Flowers  showy, 
irregular.  Corolla  tubular,  with  a  widened  throat  and  a 
5-lobed  limb.  Stamens  usually  2  long  and  2  short,  or  only  2. 
Ovary  free  from  the  calyx,  2-celled  or  rarely  1-celled,  with 
many  ovules.  Fruit  a  capsule ;  seeds  large,  winged. 

I.    BIGNONIA,  Tourn. 

Woody  vines.  Leaves  opposite,  compound,  usually  ten- 
dril-bearing. Flowers  large,  in  axillary  clusters.  Calyx 
cup-shaped,  truncate,  or  undulate-toothed.  Corolla  spreading- 
tubular,  somewhat  2-lipped,  the  lobes  rounded.  Stamens  4, 
2  long  and  2  short.  Capsule  linear,  flattened  parallel  with 
the  partition,  the  two  valves  separating  from  the  partition  at 
maturity.  Seeds  flat,  broadly  winged.* 

1.  B.  capreolata,  L.  CROSS-VINE.  Stem  climbing  high,  a  trans- 
verse section  of  the  older  stems  showing  a  conspicuous  cross  formed 
by  the  4  medullary  rays;  branches  smooth.  Leaves  evergreen, 
petioled  ;  leaflets  2,  ovate,  taper-pointed  with  a  blunt  apex,  heart- 
shaped  at  the  base,  entire,  stalked,  upper  leaflets  transformed  into 


DICOTYLEDONOUS  PLANTS  207 

branching  tendrils.  Flowers  numerous,  short-peduncled.  Corolla 
2  in.  long,  reddish-brown  without,  yellow  within.  Capsule  6  in. 
long,  flat,  the  valves  with  a  prominent  central  nerve.  Seeds  broadly 
winged  on  the  sides,  short-winged  on  the  ends.  Common  in  woods  S.* 

H.    TECOMA,  Juss. 

Woody  vines,  climbing  by  aerial  rootlets.  Leaves  com- 
pound, odd-pinnate.  Flowers  large,  in  terminal  clusters. 
Calyx  bell-shaped,  unequally  5-toothed.  Corolla  funnel-form, 
enlarged  above  the  calyx,  5-lobed,  slightly  2-lipped.  Stamens 
4,  2  long  and  2  short.  Capsule  slender,  spindle-shaped, 
slightly  compressed  contrary  to  the  partition,  2-valved,  dehis- 
cent. Seeds  winged.* 

1.  T.  radicans,  Juss.  TRUMPET  FLOWER,  TRUMPET  CREEPER. 
Stems  climbing  high  by  numerous  rootlets,  bark  shreddy.  Leaves 
deciduous,  petioled;  leaflets  9-11,  ovate  to  ovate-lanceolate,  serrate, 
short-stalked,  smooth  or  slightly  downy.  Flowers  in  short,  terminal 
racemes  or  corymbs.  Calyx  tubular,  f  in.  long.  Corolla  2-3  in.  long, 
scarlet  without,  yellow  within,  the  lobes  spreading.  Capsule  5-6 
in.  long,  curved,  often  persistent  through  the  winter.  Seeds  broadly 
winged.  On  borders  of  fields  and  in  woods  S. ;  often  cultivated.* 

III.    CATALPA,  Scop.,  Walt. 

Small  trees.  Leaves  large,  opposite,  simple,  petioled,  decid- 
uous. Flowers  large  and  showy,  in  terminal  panicles.  Calyx 
irregularly  2-lipped.  Corolla  tubular-bell-shaped,  oblique, 
5-lobed,  2-lipped.  Fertile  stamens  2,  sterile  stamens  3,  short. 
Fruit  a  linear,  2-valved,  many-seeded  capsule.  Seeds  winged.* 

1.  C.  bignonioides,  Walt.      CATALPA.     A  small  tree  with  thin, 
rough,  gray  bark  and  light,  soft,  but   exceedingly   durable   wood. 
Leaves  long-petioled,  heart-shaped,  entire  or  palmately  3-lobed,  taper- 
pointed  at  the  apex,  palmately  veined,   downy.     Branches  of  the 
panicle   in  threes  ;  flowers  large,  1-1  £  in.  long,   white,   variegated 
with  yellow  and  purple.    Corolla  lobes  undulate  or  crisped.     Capsule 
very  slender,  1  ft.  or  more  in  length,  pendulous.     Seeds  with  long, 
fringed   wings.      On    margins    of    rivers   and    swamps    S.,    often 
cultivated.* 

2.  C.'  speciosa,  Warder.     CATALPA.     A  tall  tree  with  very  durable 
wood.      Leaves  large,  heart-shaped,  taper-pointed.      Corolla  about 
2  in.  long,  almost  white,  but  slightly  spotted  ;  tube  inversely  conical ; 


208  FOUNDATIONS   OF  BOTANY 

limb  somewhat  oblique,  its  lower  lobe  notched.  Pod  rather  stout. 
Rich,  damp  woods,  especially  S.  W.  ;  often  cultivated. 

91.    OROBANCHACE.2E.     BROOM-RAPE  FAMILY. 

Leafless  brownish  root-parasites.  Kootstock  often  tuberous, 
naked  or  scaly.  Stem  usually  stout,  solitary,  scaly.  Flowers 
spiked  or  racemed.  Sepals  4-5,  free  from  the  ovary.  Corolla 
hypogynous,  irregular,  the  tube  curved ;  the  limb  2-lipped. 
Stamens  4,  2  long  and  2  short,  inserted  on  the  corolla-tube  ; 
anthers  2-celled,  the  cells  spurred  at  the  base.  Ovary  1-celled, 
of  2  carpels,  style  simple,  stigma  2-lobed ;  ovules  many.  Cap- 
sule 1-celled,  2-valved,  few-many-seeded ;  seeds  very  small. 

I.  CONOPHOLIS,  Wallroth. 

Stems  often  clustered,  stout,  covered  with  scales  which 
overlap,  the  uppermost  ones  each  with,  an  axillary  flower, 
thus  forming  a  spike.  Calyx  irregularly  4-5  cleft,  split  down 
the  lower  side.  Corolla  swollen  below,  decidedly  2-lipped,  the 
upper  lip  arched.  Stamens  projecting. 

1.  C.  americana,  Wallroth.  SQUAW-ROOT,  CANCER-ROOT.  Stems 
3-6  in.  high,  yellowish  or  yellowish-brown.  Flowers  numerous,  in- 
conspicuous. Corolla  dirty  white  or  pale  brown.  In  oak  woods, 
not  very  common. 

II.  APHYLLON,  Mitchell. 

Brownish  or  whitish  plants  with  naked  scapes  borne  on 
scaly,  mostly  underground  stems.  Calyx  regular,  5-cleft. 
Corolla  5-lobed,  slightly  irregular.  Stamens  not  projecting 
from  the  corolla-tube. 

1.  Aphyllon   uniflorum,    Gray.       ONE-FLOWERED    CANCER-ROOT. 

Slightly  covered  with  clammy  down.  Stems  very  short-branched, 
each  with  1-3  1-flowered  scapes  3-5  in.  high.  Calyx-lobes  lance- 
awl-shaped,  half  as  long  as  the  corolla.  Corolla  yellowish-white, 
veiny,  purple-tinged,  palate  with  2  yellow  bearded  ridges.  Damp 
woods. 

2.  A.  fasciculatum,  Gray.     Stem  scaly,  upright,  3-4  in.  high  above 
ground  and  generally  longer  than  the  numerous  1-flowered  pedun- 
cles.    Calyx-lobes  short,  triangular.      Parasitic  on  wild  species  of 
Artemisia,  etc.,  in  sandy  and  loamy  soil  N.  W.  and  W. 


DICOTYLEDONOUS   PLANTS  209 


92.    LENTIBULARIACE^:.     BLADDEKWORT  FAMILY. 

Scape-bearing  herbs,  chiefly  aquatic  or  living  in  marshes. 
Leaves  are  often  thread-like  and  floating,  without  stipules. 
Flowers  irregular.  Calyx  free  from  the  ovary,  persistent. 
Corolla  hypogynous,  2-lipped,  the  tube  short,  spurred  at  the 
base.  Stamens  2,  opposite  the  lateral  sepals,  hypogynous  or 
inserted  on  the  corolla-tube.  Ovary  free,  1-celled ;  style 
short,  thick,  stigma  2-lipped,  ovules  many.  Capsule  2-valved 
or  bursting  irregularly,  many-seeded. 

UTRICULARIA,  L. 

Aquatic  or  terrestrial  herbs,  often  floating  and  propagated 
by  buds  which  break  loose  from  the  plant  and  sink  to  the 
bottom  of  the  pond  or  stream  during  the  winter.  Leaves  of 
the  aquatic  species  floating,  thread-like,  furnished  with  little 
bladders  in  which  animalcules  are  caught.  Flowers  often 
rather  showy,  solitary,  spiked  or  racemed.  Corolla  with  its 
throat  nearly  closed  by  the  palate.  Capsule  globose,  bursting 
irregularly. 

1.  U.  cornuta,  Michx.    HORNED  BLADDERWORT.   Stemless.  Leaves 
linear  and  entire  or  none ;  air  bladders  few  or  none.     Scape  erect, 
stout,  2-5-flowered,  8-12  in.  high.     Flowers  yellow,  fragrant,  f  in. 
wide.     Pedicel  as  long  as  the  calyx.     Lips  of  the  corolla  obovate, 
unequal,  the  lower  longer,  abruptly  pointed,  the  sides  reflexed,  as 
long  as  the  horn-shaped,  curved  spur,  throat  bearded.    Seeds  minutely 
pitted.     In  swamps  and  muddy  places.* 

2.  U.  subulata,  L.      SMALL  BLADDERWORT.      Scape  thread-like, 
2-6  in.  high.     Leaves  few  and  awl-shaped  or  none ;  air  bladders  few 
or  none.     Racemes  zigzag,  1-6-flowered  ;  pedicels  much  longer  than 
the  calyx.     Corolla  yellow,  £  in.  wide,  the  lower  lip  3-lobed,  longer 
than  the  appressed,  conical,  green-pointed  spur.     Wet,  sandy  soil.* 

3.  U.  inflata,  Walt.     SWOLLEN  BLADDERWORT.     Perennial ;  stem 
very  slender,  floating.     Leaves  finely  dissected,  the  lower  ones  scat- 
tered,   the   upper   ones  whorled;   the  petioles  dilated  upward  and 
inflated,  air  bladders  very  numerous.     Scape  stout,  6-12  in.  high, 
3-10-flowered.     Corolla  yellow,  about  f  in.  wide,  upper  lip  ovate, 
slightly  lobed,  lower  lip  3-lobed,  twice   the  length   of  the  curved, 
emarginate  spur.     Fruit  nodding.     In  ponds  and  still  water.* 


210  FOUNDATIONS   OF  BOTANY 

4.  U.  vulgaris,  L.  GREATER  BLADDERWORT.  Stems  submerged, 
leafy,  1-3  ft.  long.  Leaves  spreading,  pinnately  cut  into  very  many 
thread-like  segments  which  bear  many  bladders.  Scapes  6-12  in. 
long,  5-12-flowered,  pedicels  bent  down  after  flowering.  Corolla  ^-| 
in.  long,  yellow,  upper  lip  broad  and  short,  palate  prominent;  spur 
conical,  pressed  close  to  the  under  lip.  Ponds  and  slowly  flowing 
streams. 

93.    ACANTHACEJE.     ACANTHUS  FAMILY. 

Herbs  or  shrubs.  Leaves  opposite  or  whorled,  without 
stipules.  Flowers  irregular,  usually  with  large  bracts.  Calyx 
of  4  or  5  unequal  segments  which  considerably  overlap  each 
other.  Corolla  4-5-parted  and  usually  more  or  less  2-lipped. 
Stamens  usually  2  long  and  2  short,  sometimes  only  2.  Ovary 
free  from  the  calyx.  Fruit  usually  a  capsule.  Seeds  not 
winged.  A  large  family,  mostly  tropical,  with  only  a  few 
insignificant  wild  species  in  the  northern  United  States. 

I.     RUELLIA,  Plumier. 

Perennial  herbs;  stems  *  swollen  at  the  joints  and  often 
between  them,  somewhat  4-angled.  Leaves  sessile  or  short- 
petioled,  mostly  entire.  Flowers  axillary,  solitary  or  clustered, 
showy,  white,  blue,  or  purple.  Calyx  2-bracted,  5-parted,  the 
divisions  linear  and  awl-shaped.  Corolla-tube  slender,  often 
much  elongated,  the  limb  spreading,  nearly  equally  5-lobed. 
Stamens  4,  2  long  and  2  short,  included  or  slightly  projecting. 
Style  slender.  Capsule  slender,  narrowed  below,  4-12-seeded.* 

1.  R.    strepens,    L.      SMOOTH   RUELLIA.      Stem   erect,    slender, 
usually  simple,  smooth  or  hairy,  1-3  ft.  high.      Leaves  ovate  to 
oblong,  acute  at  the   apex,  narrowed  below  into  a  short  petiole. 
Flowers  solitary  or  in  small   clusters,    sessile   or   short-peduncle d. 
Calyx-lobes  shorter  than  the  tube  of  the  corolla,  downy  or  fringed. 
Corolla  blue,  the  tube  l£-2  in.  long,  the  limb  1-1  £  in.  wide.     Cap- 
sule usually  longer  than  the  calyx,  smooth,  8-12-seeded.     The  later 
flowers  often  without  a  corolla.     On  rich,  dry  soil.* 

2.  R.  ciliosa,  Pursh.     HAIRY  RUELLIA.    Stem  erect,  rather  stout, 
often  few-branched  above,  covered  with  white  hairs,  4-30  in.  high. 
Leaves  oblong  to  ovate,  acute  or  obtuse  at  the  apex,  narrowed  and 


DICOTYLEDONOUS  PLANTS  211 

mostly  sessile  at  the  base,  hairy-fringed.  Flowers  pale  blue,  solitary 
or  2-3  together.  Calyx-lobes  bristle-shaped,  half  the  length  of  the 
corolla-tube.  Tube  of  the  corolla  2  in.  long.  Capsule  shorter  than 
the  calyx,  smooth,  8— 12-seeded.  A  very  variable  species,  the  flowers 
often  without  a  corolla.  In  dry  woods  and  fields  S.* 

II.     DIANTHERA,  Gronov. 

Perennial  herbs  ;  stem  smooth.  Leaves  opposite,  entire  or 
toothed.  Flowers  axillary,  solitary  or  clustered,  irregular. 
Calyx  5-parted.  Corolla  2-lipped,  upper  lip  erect,  concave, 
entire  or  notched,  the  lower  prominently  veined,  spreading, 
3-lobed.  Stamens  2,  inserted  in  the  throat  of  the  corolla. 
Ovary  2-celled,  4-ovuled,  style  simple,  acute.  Capsule  flat- 
tened, narrowed  below  into  a  little  stalk.1* 

1.  D.  americana,  L.  WATER  WILLOW.  Stem  erect,  slender,  2-3 
ft.  high.  Leaves  lanceolate  to  linear-lanceolate,  taper-pointed  at  the 
apex,  narrowed  below  to  the  sessile  or  short-petioled  base.  Flowers 
bracted,  in  short  spikes,  on  peduncles  as  long  as  the  leaves.  Corolla 
pale  blue  or  purple,  the  tube  as  long  as  the  lips,  lower  lip  wrinkled. 
Capsule  about  the  length  of  the  calyx.  In  water  S.* 


94.   PLANTAGINACEJE.     PLANTAIN  FAMILY. 

Annual  or  perennial  scape-bearing  herbs.  Leaves  usually 
all  radical,  with  parallel  ribs.  Flowers  small,  green,  usually 
spiked,  regular  and  perfect  (Fig.  21).  Sepals  4,  persistent. 
Corolla  hypogynous,  salver-shaped,  thin  and  dry ;  lobes  4, 
spreading.  Stamens  4,  usually  inserted  on  the  corolla-tube, 
filaments  thread-like,  anthers  large  and  versatile.  Ovary  free, 
usually  2-4-celled ;  style  thread-like.  Fruit  a  1-4-celled, 
1  or  more  seeded  membranous  capsule,  which  splits  open 
transversely,  the  top  coming  off  like  a  lid. 

PL  ANT  AGO,  L. 

Characteristics  of  the  genus  as  given  above  for  the  family. 

1.  P.  major,  L.  PLANTAIN.  Perennial,  from  a  very  short  root- 
stock.  Leaves  ovate  to  oval,  strongly  5-9-ribbed,  acute  or  obtuse  at 


212 


FOUNDATIONS   OF  BOTANY 


the  apex,  rounded  at  the  base  into  a  long,  concave  petiole,  entire  or 
toothed,  smooth  or  slightly  downy.  Scape  taller  than  the  leaves, 
downy,  spike  densely  flowered ;  bracts  short,  ovate.  Flowers  per- 
fect. Stamens  4,  projecting.  Capsule  ovoid,  about  twice  the  length 
of  the  calyx.  Common  in  dooryards.* 

2.  P.  lanceolata,  L.  RIBGRASS.  Biennial  or  perennial ;  soft- 
hairy  or  nearly  smooth.  Leaves  numerous,  lanceolate  to  elliptical, 
acute,  long-petioled,  strongly  3-5-ribbed,  entire 
or  toothed.  Scapes  much  longer  than  the  leaves, 
striate-angled,  1-2  ft.  high,  spike  short  and  dense. 
Bracts  and  sepals  ovate.  Corolla  smooth.  Cap- 
sule longer  than  the  calyx,  2-seeded.  Introduced; 
common  in  meadows.* 

3.  P.  aristata,  Michx.  LARGE-BRACTED  PLAN- 
TAIN.    Annual.     Leaves  broadly  linear,  entire 
or  sparingly  and  finely  toothed,  narrowed  below 
into  a  margined  petiole,  smooth  or 
silky-downy.    Scape  longer  than  the 
leaves,  6-10  in.  high,    spike   dense. 
Bracts  linear,  £-1  in.  long.    Stamens 
4  ;  capsule  2-seeded,  longer  than  the 
calyx.     Common  on  dry  soil.* 

4.  P.  heterophylla,  Nutt.  MANY- 
SEEDED  PLANTAIN.  Annual. 
Leaves  linear,  fleshy,  entire,  or  with 
a  few  spreading  teeth,  smooth  or 
slightly  downy.  Scapes  slender,  3-6 
in.  high,  spike  very  slender,  many- 
flowered,  the  lower  flowers  often 
scattered.  Bracts  ovate,  longer  than 
the  sepals.  Stamens  2.  Capsule 
twice  the  length  of  the  calyx,  many-seeded.  Common  in  cultivated 
ground,  especially  S.* 


FIG.  21.  — Flowers  of  Plantain 

(Plantago),  enlarged. 
A,  earlier  stage,  pistil  mature,  sta- 
mens not  yet  appearing  outside 
the  corolla.    B,  later  stage,  pistil 
withered,  stamens  mature. 


95.    RUBIACE^E.     MADDER    FAMILY. 

Herbs,  shrubs,  or  trees.  Leaves  opposite  and  entire,  with 
stipules  between  them,  or  appearing  whorled  since  the  stipules 
resemble  the  leaves.  Flowers  always  perfect,  frequently 
dimorphous  (as  in  Houstonia,  Mitchella,  and  Bouvardia). 
Calyx-tube  adnate  to  the  ovary;  limb  3-6-toothed.  Corolla 
regular,  inserted  on  the  calyx-tube,  as  many-lobed  as  the 
calyx.  Stamens  equal  in  number  to  the  divisions  of  the 
corolla.  Ovary  2  or  more  celled.  A  very  large  and  important 


DICOTYLEDONOUS  PLANTS  213 

family,  of  which  many  of  the  important  species,  for  instance, 
the  coffee  shrub  and  the  cinchona  tree,  are  natives  of  warm  or 
tropical  climates. 

I.    HOUSTONIA,  L. 

Annual,  biennial,  or  perennial  herbs ;  stems  erect  or  diffuse. 
Leaves  entire,  stipules  often  only  a  line  connecting  the  bases 
of  opposite  leaves.  Flowers  small,  solitary,  or  clustered. 
Calyx  4-toothed,  persistent.  Corolla  wheel-shaped  to  funnel- 
form,  4-lobed.  Stamens  4.  Ovary  2-celled,  style  slender, 
stigmas  2.  Fruit  a  2-celled,  few-many-seeded  capsule,  open- 
ing at  the  apex,  free  from  the  calyx.* 

1.  H.  coerulea,  L.     BLUETS,  INNOCENCE,  QUAKER  LADIES,  EYE- 
BRIGHT.      Perennial,  from  very  slender  rootstocks ;    stems  tufted, 
erect,  smooth,  forking,  3-6  in.  high.     Leaves  sessile,  often  hairy- 
fringed,  the  lower  spatulate,  the  upper  lanceolate.     Flowers  solitary, 
on  slender  axillary  peduncles.     Calyx  small.     Corolla   salver-form, 
blue  or  white,  yellow  in  the  throat,  smooth,  of  two  forms,  the  stamens 
projecting  and  the  style  short  in  one  form,  while  in  the  other  the 
stamens  are  short  and  the  style  projecting.     Capsule  laterally  com- 
pressed, 2-lobed,  shorter  than  the  calyx.    Common  on  open  ground.* 

2.  H.  patens,  Ell.    SMALL  BLUETS.    Annual.    Stem  erect,  branched 
at  the  base,  forking  above,  smooth,  2-4  in.  high.    Lower  leaves  oval 
to  ovate,  petioled,  the  upper  narrower  and  sessile.     Flowers  solitary, 
on  slender,  axillary  peduncles,  blue  or  white.     Calyx  small.     Lobes 
of  the  corolla  about  as  long  as  the  tube  ;  stamens  and  style  project- 
ing or  included.     Capsule  compressed,  as  long  as  the  calyx.     Com- 
mon on  dry,  open  ground.* 

3.  H.  purpurea,  L.    LARGE  BLUETS.    Perennial ;  stem  stout,  erect, 
simple    or   branched,    smooth  or   downy,  4-angled,  6-12   in.   high. 
Leaves  ovate  to  ovate-lanceolate,  sessile  or  short-petioled,  3-5-nerved, 
often  hairy-fringed  on  the  margins.     Flowers  in  terminal  cymes, 
purple  to  nearly  white.     Corolla  funnel-form,  the  tube  longer  than 
the  limb,  hairy  within.      Stamens  and  style  projecting  or  included. 
Capsule  compressed-globose,  much  shorter  than  the  calyx.     In  dry, 
open  woods.* 

Var.  longifolia,  Gray.  LONG-LEAVED  BLUETS.  Perennial.  Stem 
erect,  branched,  smooth,  4-angled,  8-12  in.  high.  Leaves  sessile, 
the  lower-  oblanceolate  or  spatulate,  the  upper  linear,  1-nerved. 
Corymbs  terminal,  few-flowered.  Corolla  light  purple  to  white,  the 
lobes  much  shorter  than  the  tube.  Capsule  compressed-globose, 
nearly  as  long  as  the  calyx.  In  dry,  open  woods.* 


214  FOUNDATIONS   OF  BOTANY 


II.     BOUVARDIA,  Salisb. 

Smooth  perennials.  Leaves  lanceolate,  thickish.  Calyx 
4-lobed,  the  divisions  slender.  Corolla  with  a  long  and  nar- 
row or  rather  trumpet-shaped  tube  and  spreading  4-lobed  limb. 
Anthers  4,  inserted  in  the  throat  of  the  corolla,  almost  sessile. 
Stigmas  2,  flat.  Capsule  globular,  2-celled,  many-seeded. 
Flowers  dimorphous. 

1.  B.  triphylla,  Salisb.    THREE-LEAVED  BOUVARDIA.    Somewhat 
shrubby.     Leaves  nearly  smooth,  ovate  or  oblong-ovate,  the  lower 
ones  in  threes,  the  upper  ones  sometimes  in  pairs.     Corolla  scarlet 
and  slightly  downy  outside. 

2.  B.  leiantha,  Benth.      DOWNY-LEAVED   BOUVARDIA.      Leaves 
rather  downy.     Corolla  deep  scarlet,  smooth  outside. 

Both  species  cultivated  from  Mexico ;  in  greenhouses. 

HI.    MITCHELLA,  L. 

A  pretty  trailing  evergreen  herb.  Leaves  roundish-ovate, 
petioled.  Flowers  fragrant,  white  or  pinkish,  dimorphous, 
growing  in  pairs,  joined  by  their  ovaries.  Calyx  -4-toothed. 
Corolla  funnel-shaped,  with  the  lobes  bearded  within.  Sta- 
mens 4,  short.  Style  1,  stigmas  4,  slender.  Fruit  double, 
composed  of  the  united  ovaries,  really  a  stone-fruit  containing 
8  seed-like  bony  nutlets,  ripening  into  tasteless  scarlet  berries 
which  cling  to  the  plant  through  the  winter. 

1.  M.  repens,  L.  PARTRIDGE  BERRY,  SQUAW  VINE,  TWO-EYE 
BERRY.  Common  in  dry  woods,  especially  under  evergreen  conif- 
erous trees. 

IV.    GALIUM,  L. 

Annual  or  perennial  herbs  ;  steins  slender,  4-angled.  Leaves 
appearing  whorled.  Flowers  small,  in  axillary  or  terminal 
cymes  or  panicles,  perfect  or  rarely  dioecious.  Calyx-tube 
short,  the  teeth  minute  or  wanting.  Corolla  wheel-shaped, 
3-4-lobed.  Stamens  3-4,  short.  Ovary  2-celled,  styles  2, 
short,  united  below.  Fruit  2,  united,  sometimes  fleshy, 
1-seeded  carpels  which  do  not  split  open.* 

1.  G.  Aparine,  L.  GOOSEGRASS.  Annual;  stem  weak,  decum- 
bent, sharply  4-angled  and  with  backward  pointing  prickly  hairs, 


DICOTYLEDONOUS  PLANTS  215 

widely  branched,  2-4  ft.  long.  Leaves  6-8  in  a  whorl,  oblanceolate, 
prickly-hairy  on  the  margins  and  midrib.  Peduncles  axillary, 
longer  than  the  leaves,  1-3-flowered ;  flowers  white.  Fruiting  pedi- 
cels erect ;  fruit  dry,  covered  with  hooked  bristles.  In  waste 
places.* 

2.  G.  circsezans,   Michx.     WILD    LICORICE.     Perennial;    stems 
several,  erect,  smooth  or  downy,  12-18  in.  high.      Leaves  4  in  a 
whorl,  oval  to  ovate,  obtuse  at  the  apex,  strongly  3-nerved,  downy. 
Cymes  long-peduncled,  repeatedly  branched.     Flowers  nearly  sessile, 
greenish-purple;  pedicels  at   length  recurved.     Fruit   with  hooked 
bristles.     In  dry,  open  woods  S.     Easily  recognized  by  the  sweet, 
licorice-like  taste  of  the  leaves.* 

3.  G.  hispidulum,  Michx.     BEDSTRAW.     Perennial,  from  yellow 
roots;    stems    diffusely   branched,    smooth   or    slightly   roughened, 
downy  at  the  joints,  erect  or  decumbent,  1-2  ft.  long.     Leaves  4  in 
a  whorl,  narrowly  oval,  acute,  rough  on  the  margins  and  mid- vein. 
Peduncles  1-3-flowered ;  flowers  white.     Pedicels  becoming  reflexed ; 
fruit  a  bluish-black,  roughened  berry.     On  dry,  sandy  soil.* 

4.  G.  triflorum,  Michx.     Perennial ;  steins  reclining  or  prostrate, 
angles  rough-bristly.     Leaves  mostly  in  sixes,  lance-oblong,  mucro- 
nate.    Flowers  usually  in  threes,  on  slender  peduncles.    Woodlands, 
especially  N". 


96.    CAPRIFOLIACE^.    HONEYSUCKLE  FAMILY. 

Mostly  shrubs.  Leaves  opposite,  without  true  stipules. 
Flowers  often  irregular.  Calyx-tube  adnate  to  the  ovary. 
Corolla  tubular  or  wheel-shaped.  Stamens  usually  as  many 
as  the  corolla-lobes  and  inserted  on  the  corolla-tube.  Fruit  a 
berry,  stone-fruit,  or  capsule. 

I.    SAMBUCUS,  Tourn. 

Shrubs  with  odd-pinnate  leaves.  Calyx-limb  minute  or 
wanting.  Flowers  very  many,  small,  white,  in  compound 
cymes.  Corolla  with  a  small,  somewhat  urn-shaped  tube  and 
a  flattish,  spreading,  5-cleft  limb.  Stamens  5.  Stigmas  3, 
sessile.  Fruit  a  globular,  pulpy  stone-fruit,  3-seeded,  appear- 
ing like  a  berry. 

1.  S.  canadensis,  L.  COMMON  ELDER.  Stems  5-10  ft.  high, 
with  a  thin  cylinder  of  wood  surrounding  abundant  white  pith. 


216  FOUNDATIONS   OF  BOTANY 

Leaflets  5-11,  oblong,  taper-pointed,  smooth.  Cymes  flat  and  often 
very  large.  Fruit  purplish-black,  insipid  or  almost  nauseous,  but 
somewhat  used  in  cookery. 

2.  S.  racemosa,  L.  RED-BERRIED  ELDER.  More  woody,  with 
brown  pith.  Leaflets  fewer,  downy  beneath,  especially  when  young. 
Cymes  panicled  and  somewhat  pyramidal.  Fruit  scarlet. 

H.    VIBURNUM,  L. 

Shrubs  or  small  trees.  Leaves  simple,  entire,  dentate  or 
lobed,  with  or  without  stipules.  Flowers  small,  white,  in 
terminal  cymes,  the  outer  flowers  of  the  cyme  sometimes 
greatly  enlarged  and  sterile.  Calyx-tube  very  small,  5-toothed. 
Corolla  wheel-shaped  or  bell-shaped,  5-lobed.  Stamens  5,  in- 
serted in  the  tube  of  the  corolla.  Ovary  1-3-celled,  1-3- 
ovuled,  but  only  1  ovule  maturing ;  style  short,  3-lobed.  Fruit 
a  1-seeded  stone-fruit.* 

A. 

Flowers  around   the  margin  of  the    cyme    without  stamens  or  pistils, 
large  and  showy. 

1.  V.    lantanoides,    Michx.  .  HOBBLE-BUSH,    WITCH-HOBBLE.     A 
shrub  about  5  ft.  high,  with  the  branches  reclining  and  often  root- 
ing and  forming  loops  (whence  the  popular  names).     Leaves  very 
large,  roundish,  abruptly  taper-pointed,  serrate,  with  a  rusty  down 
on  the  petioles  and  veinlets.     Cymes  very  broad  and  showy.     Fruit 
red,  not  eatable. 

2.  V.  Opulus,  L.     CRANBERRY  TREE,  HIGH-BUSH  CRANBERRY. 
A  handsome,  upright  shrub.     Leaves  3-5-ribbed  and  3-lobed.    Fruit 
bright  red,  juicy,  very  acid,  and  used  as  a  substitute  for  cranberries. 
Common  N.     The  form  known  as  "  Snowball "  with  all  the  flowers 
showy  and  sterile  is  cultivated  from  Europe. 

B. 

Flowers  all  small  and  perfect. 

3.  V.  acerifolium,  L.     MAPLE-LEAVED  ARROWWOOD.     A  slender 
shrub  3-6  ft.  high.     Leaves  broadly  ovate  to  heart-shaped,  palmately 
veined  and  3-lobed,  serrate  or  nearly  entire,  petioled,  downy,  becom- 
ing smooth  above.     Cymes  peduncled,  about  7-rayed,  2-3  in.  wide ; 
sterile  flowers  none.     Fruit  oval,  black,  stone  flat,  2-ridged  on  the 
edges.     In  dry,  open  woods.* 


DICOTYLEDONOUS  PLANTS  217 

4.  V.    dentatum,    L.      ARROWWOOD.      A   shrub    8-15   ft.    high. 
Leaves  broadly  ovate  to  oval,  acute  at  the  apex,  rounded  or  heart- 
shaped  at  the  base,  coarsely  dentate,  smooth  above,  hairy  in   the 
axils  of  the  veins  beneath,  short-petioled.     Cymes  long-peduncled, 
7-rayed,  2-3  in.  wide ;  sterile  flowers  none.     Calyx  smooth.     Fruit 
globose,  dark  blue,  stone  compressed,  grooved  on  one  side.     In  rich, 
damp  soil.* 

5.  V.  nudum,  L.     WITHE-ROD.     A  shrub  8—12  ft.  high.     Leaves 
ovate  to  lanceolate,  entire  or  slightly  toothed,  acute  at  both  ends, 
thick,  smooth  above,  the  veins  prominent  beneath  ;    petiole  short. 
Cymes  short-peduncled,  5-rayed  ;  sterile  flowers  none.     Fruit  ovoid, 
blue.     Common  in  swamps.* 

6.  V.  prunifolium,  L.      BLACK  HAW.      A  small  tree,  15-20  ft. 
high.     Leaves  oval  to  ovate,  acute  or  obtuse  at  each  end,  finely  and 
sharply  serrate,   smooth  and  shining  above,  often  slightly  downy 
beneath ;  petioles  dilated  and   rusty-downy.     Cymes  sessile,  large, 
4-5-rayed;  sterile  flowers  none.     Fruit  oval,  bluish-black,  eatable. 
In  rich,  moist  woods.* 


HI.    SYMPHORICARPOS,  Dill. 

Shrubs.  Leaves  short-petioled,  deciduous.  Flowers  in 
axillary  clusters.  Calyx-tube  globose,  4-5-toothed.  Corolla 
bell-shaped,  4-5-lobed,  sometimes  knobbed  at  the  base,  smooth 
or  hairy  within.  Stamens  4-5.  Ovary  4-celled,  2  of  the 
cells  with  a  single  fertile  ovule  in  each,  the  other  cells  with 
several  abortive  ovules ;  style  slender,  stigma  knobbed  or 
2-lobed.  Fruit  a  4-celled,  2-seeded  berry.* 

1.  S.  racemosus,  Michx.  SNOWBERRY.  An  ornamental  shrub, 
2-3  ft.  high.  Flowers  in  loose  terminal  racemes,  which  are  often 
leafy.  Corolla  bell-shaped,  much  bearded  inside,  pinkish-white. 
Stamens  and  style  not  projecting.  Berries  rather  large,  snow-white, 
remaining  long  on  the  branches.  Rocky  banks,  often  cultivated. 


IV.     LINNJEA,  Gronov. 

A  very  small,  slender,  creeping  evergreen  shrub ;  branches 
inclined,  ending  in  a  slender,  erect,  2-flowered  peduncle. 
Leaves  opposite,  without  stipules.  Flowers  nodding,  on  slen- 
der pedicels,  with  2  bractlets.  Calyx-tube  ovoid ;  limb  5-lobed. 
Corolla  nearly  bell-shaped,  5-lobed.  Stamens  4,  inserted  near 
the  base  of  the  corolla,  2  of  them  longer  than  the  other  2. 


218  FOUNDATIONS   OF   BOTANY 

Ovary  3-celled;  style  thread-like,  stigma  knobbed;  ovules 
many  in  1  cell,  solitary  in  the  2  others.  Fruit  nearly  globose, 
1-seeded. 

1.  L.  borealis,  L.  TWIN-FLOWER.  A  beautiful,  delicate  plant. 
Corolla  pale  pink,  very  fragrant.  Moist  woods,  in  moss,  and  cold 
bogs  N. 

V.    TRIOSTEUM,  L. 

Coarse,  hairy,  perennial  herbs.  Leaves  large,  those  of  each 
pair  somewhat  joined  at  the  base,  so  that  the  stem  appears  to 
rise  through  them.  Calyx-tube  ovoid ;  divisions  of  the  limb 
leaf-like,  lance-linear,  persistent.  Corolla  knobbed  at  the  base, 
nearly  equally  5-lobed.  Ovary  usually  3-celled,  ripening  into 
a  stone-fruit  with  3  nutlets. 

1.  T.  perfoliatum,  L.  TINKER-WEED,  WILD  COFFEE,  FEVER- 
WORT,  HORSE-GENTIAN.  Stem  unbranched,  soft-hairy,  2-4  ft.  high. 
Leaves  spatulate-ovate,  abruptly  narrowed  at  the  base,  4-7  in.  long 
and  2-4  in.  wide,  bordered  with  a  fringe  of  hairs.  Flowers  dark 
brownish-purple.  Corolla  about  \  in.  long,  sticky-downy.  Fruit 
ellipsoidal,  orange-colored  when  ripe.  Common  along  fence-rows 
and  in  rocky  woods. 

VI.    LONICERA,  L. 

Shrubs  or  woody  vines.  Leaves  simple,  usually  entire, 
those  of  a  pair  often  appearing  as  if  joined  together  at  the 
base,  so  that  the  stem  seems  to  rise  through  them.  Calyx- 
tube  ovoid,  5-toothed.  Corolla  tubular  to  bell-shaped,  often 
knobbed  at  the  base  or  2-lipped.  Stamens  5.  Ovary  2-3- 
celled,  ovules  several  in  each  cell;  style  slender,  stigma 
knobbed.  Fruit  a  1-3-celled,  1-few-seeded  berry.* 

A. 

Stems  twining. 

1.  L.  Sullivantii,  Gray.  YELLOW  HONEYSUCKLE.  Stem  some- 
what twining.  Leaves  oval  to  obovate,  obtuse,  entire,  green  above, 
with  a  bloom  beneath,  the  lower  short-petioled,  the  upper  sessile  or 
joined  at  the  base.  Flowers  in  crowded,  terminal  whorls,  bright 
yellow,  fragrant.  Corolla-tube  slender,  1-1 1  in.  long,  bilabiate, 
4-lobed,  pubescent  within.  Stamens  and  style  projecting.  On  river 
banks  and  hillsides ;  often  cultivated.* 


DICOTYLEDONOUS   PLANTS  219 

2.  L.  sempervirens,  L.    CORAL  HONEYSUCKLE,  TRUMPET  HONEY- 
SUCKLE.    Stem  twining  high.     Leaves  evergreen    (in  the  South), 
oval  to  oblong,  obtuse,  entire,  smooth  above,  pale  and  often  downy 
beneath,  the  lower  petioled,  the  upper  pair  nearly  semi-orbicular  and 
joined  at   the   base.     Flowering   spikes   terminal,   bearing   several 
whorls.     Corolla  about  2  in.  long,  slender,  smooth,  the  limb  short, 
nearly  equally  5-lobed,  scarlet  without,  bright  yellow  within.     Sta- 
mens slightly  projecting  ;  fruit  red.     On  low  ground ;  often  culti- 
vated.* 

3.  L.   japonica,  Thunb.     JAPAN   HONEYSUCKLE.     Stem  twining 
high;    young  branches   downy.     Leaves   ovate   to   oblong,    entire, 
smooth  above,  pale  and  downy  beneath,  all  short-petioled  ;  peduncles 
axillary,  2-bracted,  2-flowered ;  flowers  white  or  pink,  fading  to  yel- 
low, 2-lipped,  the  lips  nearly  as  long  as  the  downy  tube.     Stamens 
and  style  projecting.     Fruit  black.     Introduced  from  Japan ;  com- 
mon in  cultivation.* 

4.  L.  Caprifolium,  L.      EUROPEAN    HONEYSUCKLE.      A   moder- 
ately high-climbing  shrub.     Leaves  smooth  and  deciduous,  several 
of  the  upper  pairs  united  at  their  bases  to  form  a  flattish  disk  or 
somewhat  cup-shaped  leaf.     Flowers  in  a  single  terminal  whorl,  very 
sweet-scented.     Corolla  whitish,  red,  or   yellow,  2-lipped,  with  the 
lips  recurved.     Cultivated  from  Europe. 

B. 

More  or  less  upright  bushes,  not  climbing. 

5.  L.   tatarica,   L.     TARTARIAN   HONEYSUCKLE.     A    branching- 
shrub,  5-8  ft.  high.     Leaves  oval  or  ovate,  heart-shaped,  shining. 
Flowers    many,   showy,    rose-colored.      Fruit    consisting   of   2    red 
berries ;    somewhat   united   below   at   maturity.     Cultivated   from 
Asia. 

6.  L.  ciliata,  Muhl.     EARLY  FLY  HONEYSUCKLE.     A  straggling 
bush,  3-5  ft.  high.     Leaves  ovate  or  oval,  slightly  heart-shaped,  thin, 
at   first    downy  beneath.     Flowers  straw-yellow,   on  short,  slender 
peduncles.     Corolla-lobes  nearly  equal ;  tube  pouched  at  the  base. 
Fruit,  2  separate  red  berries. 

VH.    DIERVILLA,  Tourn. 

Low,  upright  shrubs.  Leaves  taper-pointed,  serrate.  Flowers 
in  loose  terminal  or  axillary  clusters  or  cymes.  Calyx  with 
a  limb  of  5  linear  divisions.  Corolla  funnel-shaped,  almost 
regularly  5-lobed.  Stamens  5.  Ovary  slender,  2-celled?  ripen- 
ing into  a  2-valved,  many-seeded  pod. 


220  FOUNDATIONS   OF  BOTANY 

1.  D.  trifida,  Moench.     COMMON  BUSH  HONEYSUCKLE.     Bushy, 
1-4  ft.  high.     Leaves  ovate  or  oblong-ovate,  petioled.     Peduncles 
1-3-flowered.     Pods   tapering    to    a  slender    point.      Rocks,    espe- 
cially X. 

2.  D.  japonica,  Thunb.     WEIGELA.     A   stout,   branching  shrub, 
3-6  ft.  high.     Leaves  broadly  oval,  acute  at  the  apex,  rounded  at 
the  base,  coarsely  serrate,  rough  above,  downy  beneath,  short-peti- 
oled.      Flowers  spreading,    funnel-form,  rose-color,  1-1  i   in.   long. 
Calyx-lobes  deciduous.     Corolla  downy  without,  the  lobes  spreading. 
Capsule  oblong  or  spindle-shaped.    Seeds  with  netted  wings.    Intro- 
duced from  Japan  ;  common  in  cultivation.* 


97.    VALERIAN  ACEJE.     VALERIAN  FAMILY. 

Herbs,  rarely  shrubs.  Leaves  opposite,  without  stipules. 
Flowers  small,  usually  irregular,  in  forking  cymes.  Calyx- 
tube  adnate  to  the  ovary.  Corolla  funnel-shaped,  the  base 
often  with  a  sac  or  spur.  Stamens  1-3  or  5,  inserted  at  the 
base  of  the  corolla-tube ;  filaments  slender,  anthers  versatile. 
Ovary  cells  3,  two  of  them  not  ovule-bearing,  the  third  with  a 
single  ovule  hanging  from  the  top ;  style  thread-like,  stigma 
blunt  or  2-3-lobed.  Fruit  small,  not  splitting  open. 

I.    VALERIAN  A,  L. 

Perennial,  rarely  annual,  herbs.  Root-leaves  crowded ; 
stem-leaves  opposite  or  whorled,  entire  or  pinnately  cut. 
Flowers  in  corymbed,  headed,  or  panicled  cymes.  Limb  of 
the  calyx  consisting  of  several  plumy  bristles.  Lobes  of 
the  corolla  5  or  rarely  3-4,  unequal.  Stamens  3.  Stigma 
knobbed.  Fruit  flattened,  ribbed,  1-celled,  1-seeded. 

1.  V.  edulis,  Nutt.     An  upright,  straight-stemmed  plant,  1-4  ft. 
high.     Leaves   all   thickish   and   closely  fringed  with  short   hairs; 
root-leaves  linear-spatulate  or  lanceolate-spatulate,  entire  ;  stem-leaves 
pinnately  parted,  the  3-7  divisions  long  and  narrow.    Flowers  almost 
dioecious,  in  a  long,  interrupted  panicle.    Corolla  whitish.    Root  long 
and  stout,  eaten  by  Indians.     Low  ground  and  wet  prairies,  especially 
N.  W. 

2.  V.  officinalis,  L.     GARDEN  VALERIAN.    Plant  smooth  or  hairy 
below,  strong-smelling.     Rootstock  short.     Leaves  all  pinnate  ;  root- 


DICOTYLEDONOUS   PLANTS  221 

leaves  long-petioled,  soon  withering;  stem-leaves  2-5  in.  long, 
sessile,  the  leaflets  lanceolate,  entire  or  serrate.  Corolla  pale 
pink.  Rootstocks  strong-scented,  used  in  medicine.  Cultivated 
from  Europe. 

H.    VALERIANELLA,  Tourn. 

Annual  herbs;  stem  forking  regularly.  Leaves  opposite, 
entire  or  dentate.  Flowers  in  crowded,  terminal,  bracted 
cymes.  Calyx-limb  toothed  or  wanting.  Corolla  white  or 
purplish,  funnel-form,  5-lobed.  Stamens  3.  Style  3-lobed. 
Fruit  3-celled,  1-seeded.* 

1.  V.  olitoria,  Poll.     LAMB   LETTUCE.     Stem   erect,   smooth,    or 
downy  at  the  nodes,  many  times  forked,  9-12  in.  high.     Basal  leaves 
tufted,  spatulate  to  obovate,  entire,  the  upper  lanceolate,  dentate, 
sessile.     Cymes  short-peduncled,  bracts  linear.     Flowers  pale  blue. 
Fruit  compressed,  oblique.     On  rich  soil  in  waste  places.* 

2.  V.  radiata,  Dufr.     CORN  SALAD.     Stem  erect,  smooth  above, 
downy  below,  2-4  times  forked,  8-12  in.  high.     Lower  leaves  spatu- 
late, entire,  the   upper   lanceolate,    clasping   at   the   base,    dentate. 
Cymes  compact ;   bracts  lanceolate.     Flowers  white.     Fruit  ovoid, 
downy,  furrowed.     On  damp  soil.* 


98.   CUCURBIT  ACE  JE.     GOURD  FAMILY. 

Somewhat  succulent,  tendril-bearing,  prostrate  or  climbing, 
herbaceous  plants.  Leaves  alternate,  with  stipules.  Flowers 
dioecious  or  monoecious,  often  gamopetalous.  Calyx-tube  ad- 
nate  to  the  ovary ;  calyx-limb  (if  present)  5-lobed.  Corolla 
usually  5-lobed  and  with  its  tube  more  or  less  united  with  the 
calyx-tube.  Stamens  perigynous  or  borne  upon  the  corolla, 
the  anthers  usually  joined  in  long,  serpentine  ridges.  Ovary 
3-celled ;  stigmas  2  or  3.  Fruit  generally  a  pepo  (like  the 
melon,  squash,  and  pumpkin),  but  sometimes  dry.  Seeds 
commonly  large  and  flat.  A  large  family,  mostly  of  tropical 
plants,  many  with  eatable  fruit,  but  some  species  poisonous. 


222  FOUNDATIONS   OF   BOTANY 


I.    CUCURBITA,  L. 

Annual  or  perennial  herbs  ;  stem  trailing  or  climbing,  2-20 
ft.  long.  Leaves  angular-lobed ;  tendrils  branching.  Flowers 
monoecious,  solitary  or  in  small  clusters.  Calyx  5-toothed,  the 
limb  deciduous.  Corolla  bell-shaped,  5-lobed.  Staminate  flowers 
with  3  stamens  and  no  pistil ;  pistillate  flowers  with  1  pistil 
and  3  imperfect  stamens.  Style  short;  stigmas  3-5,  each 
2-lobed.  Fruit  1-celled,  with  numerous  seeds  on  the  3  parietal 
placentae.* 

1.  C.  Melopepo,  L.    SUMMER  SQUASH.    Stem  rough-hairy,  angled, 
2-5    ft.    long.     Leaves  broadly  heart-shaped,  angularly  3-5-lobed, 
rough.     Flowers  yellow,  short-peduncled.     Fruit  roundish,  longitudi- 
nally compressed,  the  margin  smooth,  wavy,  or  tubercular.     Common 
in  cultivation.* 

2.  C.  verrucosa,  L.      CROOKNECK    SQUASH.      Stem  rough-hairy, 
angled  and  striate,  5-10  ft.  long.     Leaves  cordate,  deeply  5-lobed, 
very  rough,  long-petioled.     Flowers   light   yellow,    long-peduncled. 
Fruit  clavate,  the  base  often  slender  and  curved,  smooth  or  tubercu- 
late,  very  variable.     Common  in  cultivation.* 


II.    CUCUMIS,  L. 

Annual  herbs;  stems  trailing,  usually  shorter  and  more 
slender  than  in  the  preceding  genus.  Tendrils  riot  forked. 
Leaves  varying  from  entire  or  nearly  so  to  deeply  cut.  Sterile 
flowers  in  clusters,  fertile  ones  solitary  in  the  leaf-axils. 
Corolla  of  5  acute  petals,  which  are  but  little  joined  at  the 
base.  Stamens  not  evidently  united.  Style  short ;  stigmas  3, 
each  2-lobed.  Fruit  rather  long.  Seeds  not  large,  lance- 
oblong,  not  margined. 

1.  C.  sativus,  L.  CUCUMBER.  Leaves  somewhat  lobed,  the 
middle  lobe  largest.  Fruit  more  or  less  covered  when  young  with 
rather  brittle,  blackish  prickles,  which  fall  off  as  it  ripens.  Culti- 
vated from  S.  Asia.  [Other  varieties  of  the  genus  Cucumis  are  the 
muskmelon,  cantaloupe,  and  nutmeg  melon.  Other  commonly 
cultivated  genera  are  Citrullus,  the  watermelon,  and  Lagenaria,  the 
bottle-gourd.  Two  wild  genera,  Echinocyslis,  the  wild  cucumber, 
and  Sicyos,  the  star  cucumber,  which  blossom  through  the  summer 
and  autumn,  are  common  in  the  Northern  States  and  the  Middle 
West.] 


DICOTYLEDONOUS  PLANTS  223 


99.   CAMPANULACEJE.     CAMPANULA  FAMILY. 

Herbs,  with,  milky  juice.  Leaves  alternate,  without  stipules. 
Flowers  regular,  not  clustered.  Calyx  5-lobed,  adnate  to  the 
ovary.  Corolla  regular,  bell-shaped,  5-lobed.  Stamens  5, 
usually  free  from  the  corolla  and  not  coherent.  -Style  1, 
usually  hairy  above ;  stigmas  2  or  more.  Fruit  a  capsule, 
2  or  more  celled,  many -seeded. 

I.     CAMPANULA,  Tourn. 

Annual,  biennial,  or  perennial  herbs.  Flowers  solitary, 
racemed  or  spiked,  regular,  blue  or  white.  Calyx  5-lobed 
or  parted.  Corolla  wheel-shaped  to  bell-shaped,  5-lobed. 
Stamens  5,  free  from  the  corolla,  distinct,  filaments  dilated 
at  the  base.  Ovary  3-5-celled,  many-ovuled ;  style  3-parted. 
Capsule  short,  bearing  the  persistent  calyx-lobes  at  its  apex, 
many -seeded,  splitting  open  on  the  sides.* 

1.  C.  rotundifolia,  L.     HAREBELL.     A  slender,  smooth,  branching 
perennial,  5-12  in.  high.      Root-leaves  broadly  ovate-heart-shaped, 
generally  somewhat  crenate,  soon  withering.      Stem-leaves  varying 
from  linear  to  narrowly  lanceolate,  entire.     Pedicels  slender,  flowers 
solitary  or  somewhat  racemed,  the  buds  erect  but  the  fully  opened 
flower  drooping.    Calyx-teeth  erect,  awl-shaped.    Corolla  bell-shaped, 
£-1  in.  long,  its  lobes  short  and  recurved.     Rocky  hillsides,  espe- 
cially N. 

2.  C.  aparinoides,  Pursh.     MARSH  BELL-FLOWER.     Stem  angular, 
unbranched,  slender,  weak  and  leaning  on  the  grass  among  which  it 
usually  grows,  the  angles  clothed  with  minute,  backward-pointing 
prickles.      Leaves  lance-linear,   nearly   entire.      Flowers   terminal, 
about  £  in.  long,  white.     Corolla  bell-shaped.    Wet  meadows,  in  tall 
grass. 

II.     SPECULARIA,  Heister. 

Annual;  stems  slender,  angled.  Leaves  entire  or  toothed. 
Flowers  axillary,  regular,  solitary  or  in  small  clusters,  sessile, 
bracted.  Calyx-tube  slender,  3-5-parted.  Corolla  wheel- 
shaped,  5-lobed.  Stamens  with  the  filaments  flattened  and 
shorter  than  the  anthers.  Ovary  3-celled,  many-ovuled ; 
stigmas  3.  Fruit  a  prismatic,  3-celled,  many-seeded  capsule.* 


224 


FOUNDATIONS  OF  BOTANY 


1.  S.  perfoliata,  A.  DC.  SPECULARIA.  Stem  erect,  simple  or 
branched  from  the  base,  angles  roughened,  10-20  in.  high.  Leaves 
ovate  to  lanceolate,  acute  at  the  apex,  sessile,  crenate  or  entire,  the 
upper  bract-like.  Flowers  solitary  or  in  pairs.  Corolla  blue,  often 
wanting.  Capsule  cylindrical,  smaller  above.  In  waste  places.* 


100.   COMPOSITJE.     COMPOSITE  FAMILY. 

Flowers  in  a  dense  head,  on  a  common  receptacle,  sur- 
rounded by  an  involucre  composed  of  many  bracts  (Fig.  22), 


Fio.  22.  —  Flower-cluster  of  Bachelor's  Button  (Centaurea  Cyanus). 


DICOTYLKDONors    PLANTS 


225 


with  usually  5  stamens  inserted  on  the  corolla,  the  anthers 
united  into  a  tube  which  surrounds  the  style  (Fig.  23,  V). 
Cal\\  with  its  tube  adnate  to  the  ovary,  the  limb  sometimes 
wanting,  when  present  taking  the  form  of  scales,  bristles,  etc., 
known  as  i><r/>/>//s  (Fig.  24,  IT,  III).  Corolla  either  strap- 
shaped  (Fig.  25,  r)  or  tubular  (Fig.  23,  V),  in  the  former  case 


FIG.  23.  — Bachelor's  Button. 

I,  vertical  section  of  the  receptacle ;  II,  style  and  forked  stigma  (magnified) ; 
III,  corolla,  united  anthers  and  stigma  (magnified) ;  IV,  pistil  (magnified); 
pap,  pappus ;  ak,  akene  ;  V,  tubular  flower  cut  vertically  (magnified),  showing 
anther-tube,  traversed  by  the  style  ;  /,  lobe  of  corolla. 

often  5-toothed,  in  the  latter  usually  5-lobed.  Style  2-cleft 
above.  'Fruit  an  akene,  often  provided  with  means  of  trans- 
portation (Part  II,  Ch.  XXIX).  The  largest  family  of 
flowering  plants  and  among  the  most  specialized  for  insect 
pollination.  The  genera  of  the  northern  United  States  are 
divided  into  two  suborders:  I.  TUBULIFLOR^,  corolla  of  the 
perfect  flowers  tubular  and  5-lobed  ;  II.  LIGULIFLOB^E,  corollas 
all  strap-shaped  and  flowers  all  perfect, 


226 


FOUNDATIONS   OF   BOTANY 


pap 


anth- 


FIG.  24.  — Bachelor's  Button. 

I,  a  tubular  flower  (magnified) ;  anth,  the  united  anthers  ;  II,  fruit  (magnified) ; 
III,  fruit,  vertical  section  (magnified);  IV,  a  neutral  ray-flower;1  V,  ring 
of  anthers. 


FIG.  25.  — Flower-cluster  of  Yarrow  (Achillea  Millefolium),  enlarged. 

A,  head  seen  from  above  ;  J5,  longitudinal  section  ;  re,  receptacle  ;  ch,  chaff 
i,  involucre ;  r,  ray-flowers  ;  d,  disk-flowers  ;  c,  corolla ;  s,  stigma. 


1  This  is  not  precisely  homologous  with  the  ray-flowers  of  Helianthus  and  most 
rayed  Compositse,  but  is  an  enlarged  and  conspicuous  tubular  flower. 


DICOTYLEDONOUS   PLANTS  227 

I.     TUBULIFLORJE. 


Corollas  some  or  all  of  them  tubular. 
Rays  white,  pink,  or  purplish. 

Rays  many  ;  akenes  flat  ;  pappus  wanting  ;  low  herbs.  Bellis,  I. 

Rays  many  ;    akenes  cylindrical  or  winged,  grooved  ;   pappus 

wanting  ;  tall  herbs  or  shrubby.  Chrysanthemum,  VIII. 

Rays  many  ;    akenes  flat  ;    pappus  of  an  outer  row  of  minute 

scales  and  an  inner  row  of  delicate  bristles.  Erigeron,  II. 

Rays  many  ;    akenes  cylindrical  or  ribbed  ;    pappus  wanting  ; 

strong-scented  branching  herbs.  Anthemis,  VI. 

Rays  few.  Achillea,  VIT. 

Rays  yellow. 

Disk  purplish-brown.  Rudbeckia,  IV. 

Disk  yellow. 

Involucre  of  2  rows  of  bracts,  the  outer  rather  leaf-like. 

Coreopsis,  III. 
Involucre  of  reflexed  scales  ;  pappus  of  5-8  scales. 

Helenium,  V. 
Involucre  of  erect  scales  ;  pappus  of  abundant  soft  hairs. 

Senecio,  IX. 

Rays  none,  but  the    marginal  flowers  sterile  and  their  tubular 
corollas  partly  flattened  like  rays  (Fig.  24).  Centaurea,  X. 

Rays  none  and  marginal  flowers  like  the  others  ;    scales  of  the 
involucre  overlapping  in  many  rows,  prickly-pointed. 

Cirsium,  XI. 

B. 

Corollas  all  strap-shaped. 

Corollas  blue  (rarely  pinkish);  akenes  not  beaked. 

Cichorium,  XIII. 
Corollas  blue  ;  akenes  beaked.  Lactuca,  XVIII. 

1  The  characters  in  this  key  are  not  necessarily  true  of  all  species  in  the  genera 
referred  to,  but  only  of  those  described  below. 


228  FOUNDATIONS  OF  BOTANY 

Corollas  yellow. 

Akenes  truncate ;  pappus  double,  of  chaff  and  bristles. 

Krigia,  XII. 

Akenes  columnar  ;    pappus  of  tawny,  rough  bristles  ;    stem 

scape-like.  Hieracium,  XIV. 

Akenes    spindle-shaped,    not    beaked;      pappus    of    plumed 

bristles.  .  Leontodon,  XV. 

Akenes  ovoid  to  spindle-shaped,  long-beaked ;  pappus  white, 

soft,  and  abundant.  Taraxacum,  XVI. 

Akenes  nearly  as  in  XVI ;  pappus  tawny. 

Pyrrhopappus,  XVII. 

Akenes  flattened,  beaked  ;    pappus  soft,  white,  the  hairs  soon 
falling  off  separately  ;  leafy-stemmed  herbs. 

Lactuca,  XVIII. 

Akenes  flattened,  not  beaked  ;  pappus  abundant,  soft,  white ; 
leafy-stemmed,  spiny-leaved  herbs.  Sonchus,  XIX. 

I.     BELLIS,  L. 

Small  herbs.  Leaves  usually  all  radical,  petioled.  Heads 
solitary,  disk  yellow,  ray-flowers  white  or  pink ;  involucre 
bell-shaped,  bracts  in  1  or  2  rows,  green ;  receptacle  conical. 
Ray-flowers  many,  in  a  single  row,  pistillate.  Disk-flowers 
tubular,  perfect,  4-5-toothed ;  forks  of  the  style  short,  thick, 
tipped  by  roughened  cones.  Fruit  flattened,  obovate ;  pappus 
wanting. 

1.  B.  integrifolia,  Michx.    AMERICAN  DAISY.    A  branching  annual 
or  biennial  herb,  4-12  in.  high.     Upper  leaves  lanceolate  or  oblong, 
the  lower  ones  obovate-spatulate.     Heads  borne  on  slender  peduncles; 
rays  violet-purple.     Prairies,  especially  S.W. 

2.  B.  perennis,  L.      ENGLISH  DAISY,   SCOTCH  DAISY.      A  stem- 
less  perennial.     Leaves  obovate-spatulate,  smooth  or  hairy.     Heads 
f-1    in.    in   diameter,   very  pretty,  the  rays   delicate.      Cultivated 
from  Europe. 

II.     ERIGERON,  L. 

Herbs.  Leaves  usually  sessile.  Heads  many-flowered,  flat 
or  nearly  hemispherical,  the  rays  numerous,  narrow,  pistillate. 
Scales  of  the  involucre  narrow  and  overlapping  but  little. 


DICOTYLEDONOUS   PLANTS  229 

Akenes  flattish,  crowned  with  a  single  row  of  hair-like  bristles, 
or  sometimes  with  shorter  bristles  or  scales  outside  these. 
Disk  yellow,  rays  white,  pinkish,  or  purple. 

1.  E.  annuus,  Pers.      COMMON  FLEABANE.      Annual  or  biennial. 
Stem  grooved  and  stout,  branching,  2-5  ft.  high,  with  scattered 
hairs  ;  lowest  leaves  petioled,  ovate,  coarsely  toothed,  those  higher  up 
the   stem   successively   narrower,    sessile  ;    heads   in   a  large   loose 
corymb  ;  rays  short,  white  or  purplish.     Fields  and  waste  ground. 

2.  E.  strigosus,  Muhl.     DAISY  FLEABANE.     Annual  or  biennial. 
Considerably   reserribling   the   preceding   species,   but   with   entire 
leaves,  smaller  and  less  branched  stem,  smaller  heads,  and  longer 
rays.     Fields  and  pastures. 

3.  E.  bellidifolius,  Muhl.     ROBIN'S  PLANTAIN.     Perennial.     Soft- 
hairy  ;  stems  sometimes  throwing  out  offsets  from  the  base  ;  simple, 
erect,  1-2  ft.  high;    root-leaves,  obovate-obtuse,  somewhat  serrate; 
stem-leaves  few,  lance-oblong,  acute,  clasping ;  heads  rather  large, 
1—9,  on  long  peduncles,  with  50-60  long,  rather  broad,  bluish-purple 
or  reddish-purple  rays.     Thickets  and  moist  banks. 

4.  E.  philadelphicus,  L.    Perennial.    Rather  hairy ;  stems  slender, 
about  2  ft.   high ;    root-leaves  spatulate  and  toothed ;    stem-leaves 
usually  entire  and  strongly  clasping,  sometimes  with  a  heart-shaped 
or  eared  base  ;  heads  several,  small,  long-petioled  ;  rays  exceedingly 
numerous,  thread-like,  reddish-purple  or  flesh-color.    In  damp  soil. 

in.   COREOPSIS,  L. 

Annual  or  perennial  herbs.  Leaves  opposite  or  the  upper 
alternate,  entire  or  pinnately  divided.  Heads  radiate,  solitary 
or  corymbed,  many -flowered ;  bracts  in  2  rows  of  about  8  each, 
the  inner  membranaceous  and  appressed,  the  outer  narrower 
and  spreading ;  receptacle  chaffy.  Ray-flowers  neutral ;  disk- 
flowers  tubular,  perfect.  Akenes  compressed,  oval  to  oblong, 
often  winged.  Pappus  of  2  scales  or  bristles,  or  wanting.* 

1.  C.  tinctoria,  Nutt.    GARDEN  COREOPSIS.    Annual.    Stem  erect, 
smooth,  branched,  2-3  ft.  high.    Leaves  2—3  times  pinnately  divided, 
the  divisions  linear,  lower  leaves  petioled,  the  upper  often  sessile  and 
entire.     Heads  1-1 1  in.  wide,  on  slender  peduncles  ;  inner  bracts 
brown  with  scarious  margins,  outer  bracts  very  short.     Ray-flowers 
about  8,  yellow  with  a  brown  base,  3-lobed  at  the  apex.    Akenes 
linear.     Pappus  minute  or  none.     Common  in  gardens.* 

2.  C.  lanceolata,  L.     TICKSEED.     Perennial;    stem    slender,  erect 
or  ascending,  smooth  or  slightly  downy  below,  simple,  9-15  in.  high. 
Leaves  opposite,  the  lower  spatulate  to  elliptical,  sometimes  lobed, 


230  FOUNDATIONS   OF   BOTANY 

on  long,  hairy-fringed  petioles,  the  upper  lanceolate,  sessile.  Heads 
few,  on  long  peduncles  ;  bracts  ovate-lanceolate,  the  outer  narrower. 
Ray-flowers  6-10,  rays  3-5-lobed,  bright  yellow.  Akenes  oval, 
broadly  winged,  warty.  Pappus  of  2  teeth.  On  rich,  dry  soil  S. 
and  E.* 

3.  C.  auriculata,  L.  RUNNING  TICKSEED.  Perennial;  stem  ascend- 
ing or  decumbent,  weak,  smooth,  nearly  simple,  6-15  in.  long. 
Leaves  ovate  to  oval,  entire  or  with  2-4  small  and  rounded  lobes  at 
the  base,  downy,  long-petioled.  Heads  1-1^  in.  wide,  few  or  single ; 
outer  bracts  narrower  than  the  inner.  Rays  6-10,  mostly  4-toothed 
at  the  apex  ;  chaff  as  long  as  the  flowers.  Akenes  oblong,  the  wings 
narrow  and  thickened.  Pappus  of  2  minute  teeth.  In  rich  woods.* 

IV.    RUDBECKIA,  L. 

Perennial  'or  biennial.  Leaves  alternate,  entire  or  lobed. 
Heads  radiate,  long-peduncled,  many-flowered;  bracts  imbri- 
cated in  2-3  series,  spreading ;  receptacle  convex  or  long-coni- 
cal, with  concave,  chaffy  scales.  Ray -flowers  yellow,  neutral ; 
disk-flowers  purple  to  brown,  perfect.  Akenes  smooth, 
4-angled,  truncate.  Pappus  a  few  short  teeth  or  wanting.1* 

1.  R.  hirta,  L.  CONE-FLOWER.  Annual  or  biennial ;  stem  erect, 
rough-hairy,  simple  or  branched,  2-3  ft.  high.  Leaves  lanceolate  to 
oblong,  thick,  obscurely  serrate,  rough-hairy,  3-ribbed,  the  lower 
petioled,  the  upper  sessile.  Heads  few,  long-peduncled ;  bracts 
rough-hairy,  spreading.  Ray-flowers  10-20,  orange-yellow;  disk- 
flowers  purplish  brown.  Chaff  acute,  hairy  at  the  apex.  Pappus 
none.  On  dry,  open  ground. 

V.    HELENIUM,  L. 

Annual  or  perennial.  Leaves  alternate,  forming  wings  on 
the  stem.  Heads  radiate,  peduncled,  many  -flowered ;  bracts 
in  2  series,  the  outer  linear  and  spreading,  the  inner  few  and 
scale-like ;  receptacle  naked,  convex  or  oblong.  Ray-flowers 
pistillate  and  fertile,  or  neutral,  the  rays  wedge-shaped,  3-5- 
lobed  ;  disk-flowers  perfect,  tubular,  4-5-lobed.  Akenes  top- 
shaped,  hairy,  ribbed.  Pappus  of  4-5  entire,  toothed  or  awned 
scales.* 

1.  H.  nudiflorum,  Nutt.  SNEEZEWEED.  Perennial;  stem  slender, 
erect,  downy,  branched  above,  1-2  ft.  high.  Leaves  lanceolate, 
entire  or  slightly  toothed,  the  lower  petioled,  the  upper  sessile. 


DICOTYLEDONOUS  PLANTS  231 

Heads  numerous.  Ray-flowers  10-15,  neutral,  yellow  or  yellow  and 
brown  ;  disk-flowers  purple.  Akenes  hairy  on  the  ribs ;  pappus  of 
ovate,  minutely  toothed,  awned  scales.  Common  on  river  banks  S.* 

VI.    ANTHEMIS,  L. 

Aromatic  or  ill-scented  herbs.  Leaves  finely  pinnately 
divided.  Heads  many-flowered,  with  ray-flowers.  Kays  pis- 
tillate or  neutral.  Involucre  of  many  small,  dry,  close-pressed 
scales.  Akenes  nearly  cylindrical,  generally  ribbed;  barely 
crowned  or  naked  at  the  summit. 

1.  A.  Cotula,  DC.  MAYWEED,  DOG-FENNEL.  Leaves  irregularly 
cut  into  very  many  narrow  segments.  Heads  small,  produced  all 
summer.  Disk  yellow.  Rays  rather  short,  white,  neutral.  A  low, 
offensive-smelling  annual  weed,  by  roadsides  and  in  barnyards. 

VH.     ACHILLEA,  L. 

Perennial ;  leaves  alternate,  pinnately  divided.  Heads  with 
ray -flowers  in  a  terminal  corymb  ;  involucral  bracts  imbricated 
in  several  series,  the  outer  shorter ;  receptacle  chaffy.  Ray- 
flowers  white  or  pink,  pistillate  and  fertile ;  disk-flowers  per- 
fect, tubular,  5-lobed.  Akenes  oblong,  compressed,  slightly 
margined.  Pappus  none.* 

1.  A.  Millefolium,  L.  YARROW.  Stems  often  clustered,  erect 
from  a  creeping  rootstock,  simple,  downy  or  woolly,  1-2  ft.  high. 
Leaves  lanceolate  or  oblong,  the  segments  finely  cut  and  divided, 
smooth  or  downy,  the  lower  petioled,  the  upper  sessile.  Heads 
small,  numerous,  in  flat-topped  corymbs ;  bracts  downy.  Ray-flowers 
4-5,  white  or  pink,  rays  3-lobed  at  the  apex.  Common  in  old  fields.* 

VHI.    CHRYSANTHEMUM,  Tourn. 

Perennials,  with  toothed,  pinnately  cut  or  divided  leaves. 
Heads  nearly  as  in  the  Anthemis,  except  that  the  ray-flowers 
are  pistillate. 

1.  C.  Leucanthemum,  L.  OXEYE  DAISY,  WHITEWEED,  BULL'S- 
EYE,  SHERIFF  PINK.  Stem  erect,  unbranched  or  nearly  so,  1-2  ft. 
high;  root-leaves  oblong-spatulate,  petioled,  deeply  and  irregularly 
toothed ;  stem-leaves  sessile  and  clasping,  toothed  and  cut,  the  upper- 
most ones  shading  off  into  bracts.  Heads  terminal  and  solitary, 


232  FOUNDATIONS   OF   BOTANY 

large  and  showy,  with  a  yellow  disk  and  many  white  rays.  A  trouble- 
some but  handsome  perennial  weed.  Introduced  from  Europe, 
chiefly  E. 

2.  C.  frutescens,  L.  MARGUERITE.  Erect,  branching,  perennial, 
woody  below,  smooth,  and  with  a  pale  bloom.  Divisions  of  the 
leaves  linear,  with  the  uppermost  leaves  often  merely  3-cleft  bracts. 
Heads  long-peduncled,  showy,  with  a  yellow  disk  and  large,  spread- 
ing white  rays.  Cultivated  in  greenhouses  ;  from  the  Canary  Islands. 

IX.    SENECIO,  Tourn. 

Annual  or  perennial ;  stems  often  hollow.  Leaves  alternate, 
entire  or  pinnately  divided.  Heads  with  or  without  rays,  in 
terminal  corymbs  ;  bracts  mostly  in  a  single  row,  often  with  a 
few  shorter  ones  at  the  base  ;  receptacle  naked  or  pitted.  Eay- 
flowers  yellow  or  orange,  pistillate  and  fertile  when  present ; 
disk-flowers  tubular,  perfect.  Akenes  cylindrical  or  com- 
pressed, not  beaked  or  winged,  5-10-ribbed,  downy.  Pappus 
of  numerous,  slender,  white  hairs.* 

1.  S.  tomentosus,  Michx.    WOOLLY  RAGWEED.   Perennial ;  woolly 
throughout ;  stem  stout,  erect,  mostly  simple,  2-3  ft.  high.     Lower 
leaves  ovate  to  oblong,  crenate  or  entire,  obtuse,  long-petioled ;  stem- 
leaves  few,  elliptical  to  oblanceolate,  serrate  or  toothed,  acute,  sessile. 
Heads   radiate,   f  in.  wide,  on  slender  peduncles;  bracts  narrow, 
becoming  smooth.     Ray-flowers  12-15,  yellow.     Akenes  hairy.     On 
damp  soil.* 

2.  S.  aureus,  L.     GOLDEN  RAGWEED.      Perennial  ;  stems  often 
tufted,  erect,  slender,  woolly  when  young,  branched  above,  18-30  in. 
high.     Lower  leaves  broadly  ovate,  obtuse  at  the  apex,  heart-shaped 
at  the  base,  crenate,  long-petioled ;  stem-leaves  lanceolate  and  often 
pinnatifid,  the  upper  small  and  sessile.     Heads  radiate,  corymbed, 
on   slender    peduncles;    ray-flowers    8-12,    bright   yellow.     Akenes 
smooth.     On  wet  soil ;  very  variable.* 

3.  S.  lobatus,  Pers.     BUTTERWEED.    Annual ;  stem  erect,  ridged, 
hollow,  often  woolly  when  young,  and  becoming  smooth  with  age, 
branched  above,   1-3  ft.   high.     Leaves  lyrate-pinnatifid,  thin,  the 
lower  petioled,   the   upper   sessile.     Heads   radiate   in   a   terminal 
corymb ;    bracts    linear,    acute.        Ray-flowers    about    12,    yellow. 
Akenes  slightly  rough-hairy  on  the  angles.     Pappus  rough,  longer 
than  the  involucre.     Common  on  low  ground.* 


DICOTYLEDONOUS  PLANTS  233 


X.     CENTAUREA,  L. 

Herbs.  Leaves  entire  or  cut,  often  spiny-toothed.  Heads 
single ;  involucre  ovoid  or  globose  (Fig.  22) ;  bracts  closely 
overlapping,  entire,  dry  and  membranaceous.  Corollas  all 
tubular,  oblique  or  2-lipped,  inflated  above ;  the  outer  ones 
usually  larger  and  neutral,  the  inner  flowers  perfect ;  lobes  5, 
slender.  Akenes  flattened.  Pappus  hairs  short,  slender,  rough. 

1.  C.  Cyanus,  L.  BACHELOR'S  BUTTON.  Stem  erect,  slender, 
grooved,  1-2  ft.  high,  somewhat  branched.  Leaves  acute,  sessile, 
narrow,  entire  or  few-lobed.  Peduncles  covered  with  cottony  wool. 
Heads  £-1  in.  in  diameter,  cobwebby.  Ray-like  flowers  few,  large, 
bright  blue  or  pink  ;  those  of  the  disk  smaller.  Cultivated  from 
Europe  and  escaped  from  gardens. 


XI.    CIRSIUM,  Tourn. 

Biennial  or  perennial;  stem  erect,  simple  or  branched. 
Leaves  alternate,  prickly,  often  forming  wings  on  the  stem. 
Heads  discoid,  terminal  and  solitary  or  corymbed,  many-flow- 
ered; bracts  overlapping  in  many  series,  the  outer  shorter, 
usually  spine-pointed ;  receptacle  bristly.  Corollas  purplish 
or  nearly  white,  the  tube  slender,  deeply  5-cleft.  Akenes 
oblong,  4-angled,  smooth  or  ribbed.  Pappus  of  numerous 
simple  or  plumose  bristles.* 

1.  C.  altissimum,  Spreng.     TALL    THISTLE.     Perennial  or  bien- 
nial ;  stem   stout,  very  leafy,  downy  or  woolly,  branched  4-10  ft. 
high  ;  leaves  rough-downy  above,  hoary  beneath,  fringed  with  fine 
prickles,  not  forming  wings  on  the  stem,  the   lower  petioled  and 
often  pinnately  cut,  the  upper  sessile  and  entire.    Heads  ovoid,  1  in. 
in  diameter  ;  bracts  viscid,  webby  when  young,  all  except  the  inner 
ones  tipped  with  weak  and  spreading  bristles.    Flowers  light  purple. 
Common  in  fields,  woods,  and  waste  places.* 

2.  C.  horridulum,  Michx.     YELLOW  THISTLE.     Biennial  or  peren- 
nial ;  stem  erect,  stout,  woolly  when  young,  becoming  smooth,  often 
purple,  branched  1-3  ft.  high.      Leaves  pinnately  cut,  with  very 
spiny  teeth,  mostly  sessile  and  clasping,  smooth  and  green  on  both 
sides.     Heads  large,  surrounded  by  a  whorl  of  linear-oblong,  comb- 
like  leaves  ;  involucral  bracts  linear,  ciliate,  not  spine-tipped.    Flowers 
purple  or  yellowish.     On  sandy  soil  E.  and  S.* 


234  FOUNDATIONS  OF  BOTANY 

II.     LIGULIFLORJE. 
XH.    KRIGIA,  Schreber. 

Small,  annual  or  perennial  herb.  Leaves  mostly  radical, 
toothed  or  lyrate.  Heads  several-many-flowered;  scales  of 
the  involucre  about  2-rowed,  thin.  Akenes  short,  truncate. 
Pappus  in  2  rows,  the  outer  one  of  thin,  blunt,  chaffy  scales, 
the  inner  one  of  slender  bristles.  Corollas  yellow. 

1.  K.  virginica,  Willd.      Annual ;    scapes  usually  2-5  from  one 
root,  slender.     Leaves  mostly  lyrate,  smooth  and  with  a  bloom,  the 
earlier  ones  rounded  or  spatulate.     Scales  of  the  involucre  linear- 
lanceolate,  nearly   equal,  spreading.      Akenes  top-shaped,  reddish- 
brown,  crowned  with  5  wedge-obovate  scales  and  5  rough  white 
bristles. 

2.  K.   Dandelion,  Nutt.      Perennial,   from  slender  tuber-bearing 
roots.     Scapes  leafless,  6-18  in.  high.     Leaves  entire  or  nearly  so, 
varying  from  spatulate-oblong  to  linear-lanceolate.      Akenes  more 
slender  than  in  No.  1.     Pappus  consisting  of  10-15  small,  oblong, 
chaffy  scales  and  15-20  bristles.     In  moist  ground,  especially  S. 

3.  K.  amplexicaulis,  Nutt.     Stem  12-18  in.  high,  often  2-3  from 
the  same  root,  mostly  2-forked  or  3-forked  at  the  summit.     Root- 
leaves  3-6  in.  long,  lanceolate,  entire,  toothed  or  rarely  pinnately 
cut,  clasping  at  the  base  ;    stem-leaves  1-3.      Akenes  and  pappus 
about  as  in  No.  2.     Moist  banks. 

XIII.     CICHORIUM,  L. 

Perennial  herbs  with  spreading  branches ;  juice  milky. 
Leaves  radical  and  alternate,  toothed  or  pinnately  cut.  Heads 
axillary ;  involucre  cylindrical,  bracts  in  2  rows,  the  inner 
row  erect,  coherent  at  the  base,  the  outer  shorter ;  receptacle 
flattish.  Corollas  blue,  pale  pink,  or  yellow.  Upper  part  of 
the  style  and  its  slender  arms  hairy.  Akenes  crowded  on  the 
hardened  receptacle,  firmly  covered  by  the  stiff  involucre, 
obovoid  or  top-shaped,  not  beaked.  Pappus  1  or  2  rows  of 
short  scales. 

1.  C.  Intybus,  L.  CHICORY,  BLUE  DANDELION,  BLUE  SAILORS. 
Root  very  long,  stout,  and  fleshy.  Stem  1-3  ft.  high,  angled  and 
grooved  ;  branches  straight  and  stiff.  Root-leaves  and  lower  stem- 
leaves  runcinate  ;  upper  stem-leaves  oblong  or  lanceolate,  clasping, 


DICOTYLEDONOUS   PLANTS  235 

those  of  the  branches  reduced  to  bracts.  Flowers  very  showy, 
usually  bright  blue,  rarely  pinkish-white.  Introduced  from  Europe ; 
a  troublesome  weed  in  grass-lands  and  common  in  waste  places, 
particularly  in  New  England. 

XIV.  HIERACIUM,  L. 

Perennial  herbs,  often  covered  with  glandular  or  star-shaped 
hairs  ;  juice  milky.  Leaves  alternate.  Heads  solitary,  or  in 
corymbs  or  panicles ;  bracts  of  the  involucre  many,  overlap- 
ping, unequal ;  receptacle  flattish,  naked,  pitted.  Corollas 
yellow,  rarely  orange;  arms  of  the  style  slender  and  upper 
part  of  the  style  hairy.  Akenes  angled  or  grooved,  not  beaked. 
Pappus  hairs  in  a  single  row,  simple,  stiff,  tawny,  or  brownish, 
brittle. 

1.  H.  venosum,  L.  RATTLESNAKE  WEED.  Stem  scape-like, 
usually  leafless  or  nearly  so,  smooth,  1-2  ft.  high.  Root-leaves  2-5 
in.  long,  obovate  or  ovate-oblong,  generally  purple-veined.  Heads 
rather  large,  yellow,  in  a  loose  panicled  corymb.  Dry  hills  and 
roadsides,  and  in  pine  woods  E. 

XV.  LEONTODON,  L. 

Perennial,  scape-bearing  herbs;  juice  milky.  Leaves  all 
radical,  toothed  or  pinnatifid,  often  runcinate.  Heads  on 
simple  or  branched  scapes,  yellow;  bracts  of  the  involucre 
many,  in  several  rows,  the  anther  smaller ;  receptacle  flat, 
naked.  Arms  of  the  style  linear,  obtuse,  hairy.  Akenes  cylin- 
drical, grooved,  transversely  wrinkled ;  beak  short ;  pappus 
hairs  stiff,  in  1  or  2  rows. 

1.  L.  autumnalis,  L.  Scape  usually  branching,  5-15  in.  high, 
bracted ;  peduncles  enlarged  above.  Rootstock  truncate.  Heads 
l£-l  in.  or  more  in  diameter ;  involucre  top-shaped  or  bell-shaped. 
Pappus  of  a  single  row  of  tawny  hairs.  Fields  and  roadsides, 
especially  N.  E.  Introduced  from  Europe. 

XVI.     TARAXACUM,  Haller. 

Stemless,  perennial  or  biennial  herbs.  Leaves  in  a  flattish 
tuft,  pinnately  cut  or  runcinate  (Fig.  38).  Head  many- 
flowered,  large,  solitary,  yellow,  borne  on  a  hollow  scape,  which 


236  FOUNDATIONS   OF   BOTANY 

is  short  at  first  but  lengthens  after  flowering.  Involucre  com- 
posed of  a  single  row  of  long,  erect,  inner  scales  and  a  set  of 
much  shorter  ones  outside  and  at  the  base  of  the  former  ones. 
Akenes  cylindrical  or  spindle-shaped,  with  4-5  rough  ribs,  the 
apex  tapering  into  a  bristle-like  beak  which  bears  a  short, 
broadly  conical  tuft  of  soft  white  hairs. 

1.  T.  officinale,  Weber.  DANDELION.  Outer  involucre  reflexed  ; 
inner  involucre  closing  over  the  head,  after  the  flowers  are  withered, 
and  remaining  shut  for  some  days,  then  opening  and  allowing  the 
akenes  to  form  a  globular  head.  Root  stout,  bitter,  medicinal. 
Young  leaves  eaten  as  a  pot-herb  ("greens")  in  spring — the  plant 
often  cultivated  for  the  leaves  by  market-gardeners. 

XVII.    PYRRHOPAPPUS,  DC. 

Annual  or  biennial ;  stem  erect,  leafy  below,  nearly  naked 
above,  smooth.  Leaves  oblong,  toothed  or  pinnatifid.  Heads 
large,  long-peduncled ;  involucre  cylindrical  or  spreading,  the 
inner  row  of  bracts  erect,  united  at  the  base,  the  outer  rows 
shorter  and  spreading;  receptacle  naked.  Flowers  yellow; 
rays  truncate,  5-toothed  at  the  apex.  Akenes  oblong,  5-ribbed, 
narrowed  above  into  a  long  and  slender  beak ;  pappus  soft, 
tawny,  with  a  short,  soft-hairy  ring  at  the  base.* 

1.  P.  carolinianus,  DC.  FALSE  DANDELION.  Annual  or  bien- 
nial ;  stem  glabrous,  furrowed,  branched  above,  2-3  ft.  high.  Lower 
leaves  lanceolate  to  oblong,  entire,  toothed  or  pinnatifid,  narrowed 
into  a  margined  petiole,  the  upper  sessile,  bract-like,  entire.  Heads 
few,  long-peduncled,  peduncles  and  involucre  sometimes  finely 
downy;  inner  bracts  calloused  at  the  apex,  the  outer  awl-shaped 
and  spreading.  Akenes  much  shorter  than  the  thread-like  beak. 
Common  in  fields.* 

XVIII.    LACTUCA,  Tourn. 

Annual,  biennial,  or  perennial ;  stems  leafy.  Leaves  entire 
to  pinnately  cut.  Heads  panicled;  involucre  cylindrical, 
bracts  unequal,  overlapping  in  2  or  more  rows,  the  outer 
shorter ;  receptacle  naked.  Flowers  blue,  yellow,  or  white ; 
rays  truncate,  5-toothed  at  the  apex.  Akenes  compressed, 
ribbed,  the  apex  contracted  into  a  slender  beak,  which  is 
enlarged  into  a  disk  bearing  the  soft,  hairy,  white  or  tawny 
pappus,* 


DICOTYLEDONOUS  PLANTS  237 

1.  L.   canadensis,  L.      WILD  LETTUCE.      Biennial ;   stem   erect, 
smooth,  hollow,  branched  above,  3-10  ft.  high.     Leaves  lanceolate 
to  spatulate,  pale  beneath,  the  lower  petioled  and  pinnately  cut,  the 
upper  sessile,  clasping,  and  nearly  entire.     Heads  numerous,  about 
20-flowered.     Flowers  yellow  ;    akenes  oval,  flat,  1-ribbed  on  each 
side,  minutely  roughened,  about    as   long   as   the    beak.     Pappus 
white.     In  waste  places.* 

2.  L.    acuminata,    Gray.     BLUE    LETTUCE.      Stem   very    leafy, 
smooth,  paniculately  branched  above,  3—6  ft.  high.     Leaves  ovate  to 
lanceolate,  taper-pointed,  often  hairy  beneath,  the  lower  on  winged 
petioles  and  often  sinuate-lobed,  the  upper  sessile.     Heads  racemed, 
on  divergent  and  bracted  peduncles.    Flowers  blue.    Akenes  slightly 
compressed,  beak  very  short.     Pappus  white.     In  waste  places.* 

XIX.    SONCHUS,  L. 

Annual  or  perennial.  Leaves  mostly  toothed  or  pinnately 
cut,  prickly  margined.  Heads  in  corymbs  or  panicles  ;  bracts 
in  several  series,  the  outer  shorter ;  receptacle  naked.  Flowers 
yellow,  rays  truncate,  5-toothed  at  the  apex.  Akenes  oval  to 
oblong,  compressed,  ribbed,  truncate  at  the  apex.  Pappus  of 
numerous  soft  white  hairs.* 

1.  S.  oleraceus,  L.     Sow  THISTLE.    Annual;  stem  erect,  branched, 
smooth,  2-6  ft.  high.     Leaves  spiny-toothed,  the  lower  long-petioled, 
very  irregularly  cut  or  pinnatifid,  the  upper  clasping  by  an  eared 
base.     Involucre  downy  when  young.     Akenes  channeled  and  trans- 
versely wrinkled.     In  waste  places  on  very  rich  soil.* 

2.  S.  asper,  Vill.     SPINY  Sow   THISTLE.     Annual;   stem  erect, 
smooth,  branched  but  little,  2-6  ft.  high.     Leaves  undivided,  spatu- 
late to  oblanceolate,  fringed  with  spiny  teeth,  the  lower  narrowed 
into  a  petiole,  the  upper  clasping  by  an  eared  base,  the  ears  rounded. 
Heads  numerous  ;  involucre  glabrous.     Akenes  flattened,  margined, 
3-nerved  on  each  side,  smooth.     In  waste  places.* 


GLOSSARY 

OF   TECHNICAL   TERMS   USED   ONLY   IN   THE   FLORA 


Abortive,  imperfectly  developed. 

Appressed,  lying  flat  throughout  its 
length,  used  of  such  parts  as 
bracts. 

Awl-shaped,  narrow  and  tapering 
to  a  point. 

Awned,  having  a  bristle-like  ap- 
pendage. 

Awnless,  not  awned. 

Capitate,  (1)  having  a  round  head 

like  the  stigma  of  a  primrose  ; 

(2)  growing  in  heads. 
Carpellary,  relating  to  a  carpel. 
Chaff,    small  membranous  scales, 

such  as  are  found  on  disks  of 

Composite. 
Clasping,   partly   surrounding   the 

stem,  said  of  the  bases  of  leaves. 
Claw,  the  narrowed  base  of  a  petal. 
Cleft,  cut  halfway  down. 
Coated  (bulbs),   those  with  scales 

which  completely  cover  them,  as 

in  the  onion. 
Cone,  the  fruit  of  pines,  etc.,  with 

ovule-bearing  scales. 
Connate,  united,   said  of  opposite 

leaves  which  appear  as  if  grown 

together  at  their  bases. 
Cordate,  heart-shaped. 
Corm,  a  bulb-like,  fleshy  stem  or 

base  of  a  stem. 


Crown,  an  inner  appendage  to  a 
petal  or  to  the  throat  of  the  co- 
rolla. 

Deciduous,  falling  as  petals  do  after 
blossoming,  or  as  leaves  of  most 
trees  except  evergreens  do. 

Declined,  directed  obliquely. 

Decumbent,  reclining,  but  with  the 
summit  somewhat  erect. 

Dehiscent,  splitting  into  definite 
parts. 

Diffuse,  spreading  widely  or  loosely. 

Disk,  (1)  an  outgrowth  of  the  re- 
ceptacle within  the  calyx  or 
within  the  corolla  and  stamens  ; 
(2)  the  central  part  of  the  head 
(all  but  the  rays)  in  Composite. 

Dissected,  deeply  divided  or  cut 
into  many  segments. 

Drupe,  a  stone-fruit  such  as  a  peach 
or  a  plum. 

Equitant,  leaves  astride  of  those 
within  them,  thus  appearing  in  a 
cross-section  like  the  diagram, 


Even-pinnate,  abruptly  pinnate,*,  e.  , 
with  no  leaflet  at  the  end. 

Fascicle,  a  close  cluster  or  bundle 
of  flowers,  leaves,  stems,  or  roots. 


240 


FOUNDATIONS   OF  BOTANY 


Fertile,  capable  of  producing  fruit ; 

fertile  flowers,  those  which  have 

pistils. 

Filiform,  thread-shaped. 
Fleshy,  succulent,  thick  and  full  of 

sap. 
Funiculus,    the  little  stalk  which 

connects  a  seed  or  ovule  with  the 

placenta. 

Gland,  (1)  a  structure  which  secretes 
something,  as  the  knobs  on  the 
hairs  of  sundew ;  (2)  any  knob 
or  swelling. 

Herbaceous,  with  no  stem  above- 
ground  which  lives  through  the 
winter,  not  woody  or  shrubby. 

Indefinite,  too  many  to  be  easily 
counted. 

Indehiscent,  not  splitting  open  reg- 
ularly. 

Involucrate,  provided  with  an  in- 
volucre. 

Keel,  the  two  anterior  and  united 
petals  of  a  papilionaceous  corolla. 

Key,  a  winged  fruit  like  that  of  the 
ash  or  maple. 

Limb,  the  border  or  spreading  part 
of  a  gamopetalous  calyx  or  co- 
rolla. 

Lobed,  having  divisions,  especially 
rounded  ones. 

Nerved,  having  simple  or  un- 
branched  veins  or  slender  ribs. 

Ob,  in  composition,  signifies  in- 
versely, as  obcordate,  inversely 
heart-shaped. 


Odd-pinnate,  pinnate  with  a  single 
leaflet  at  the  end  of  the  midrib. 

Palate,  a  projection  in  the  throat 
of  a  corolla. 

Papilionaceous,  butterfly  -  shaped, 
like  the  corolla  of  the  sweet  pea. 

Papillose,  covered  with  papillae  or 
minute  projections,  like  the 
human  tongue. 

Pappus,  tufts  of  hair  or  other  ob- 
jects, representing  the  limb  of  the 
calyx  in  Composttce. 

Perfoliate,  with  the  stem  appar- 
ently growing  up  through  a  leaf, 
as  in  some  honeysuckles. 

Persistent,  not  deciduous. 

Pinnatifid,  pinnately  cleft. 

Pistillate,  having  pistils  but  not 
stamens. 

Pubescent,  clothed  with  soft  hair, 
downy. 

Punctate,  marked  with  dots,  de- 
pressions, or  translucent  glands. 

Kadical,  arising  from  the  root  or  a 
very  short  stem  at  its  summit,  as 
the  leaves  of  the  dandelion. 

Reflexed,  bent  or  turned  abruptly 
downward  or  backward. 

Root-parasite,  a  plant  parasitic  on 
the  roots  of  another. 

Sagittate,  arrow-shaped. 

Scape,  a  leafless  flower-stalk  aris- 
ing from  the  ground,  as  in  the 
dandelion  and  cyclamen. 

Scarious,  thin,  dry,  and  membra- 
nous, not  green. 

Sessile,  without  a  stalk. 

Simple  (stem),  unbranched. 


GLOSSARY 


241 


Spadix,  a  spike  with  a  fleshy  axis, 
like  that  of  the  Indian  turnip  or 
the  "caJla." 

Spathe,  a  large  bract  which  encloses 
a  flower-cluster,  often  a  spadix. 

Staminate,  having  stamens  only. 

Standard,  the  posterior  petal  of  a 
papilionaceous  corolla. 

Sterile,  (1)  barren,  as  a  flower  with- 
out a  pistil  or  an  antherless  sta- 
men ;  (2)  staminate  or  male,  said 
of  flowers. 

Striate,  marked  with  fine  longitudi- 
nal parallel  lines. 

Sub-  (in  composition),  somewhat,  as 
subglobose. 

Subtend,  to  extend  beneath,  as  a 
bract  in  the  axil  of  which  a 
flower  is  borne. 

Succulent,  fleshy  or  juicy. 

Three-ranked,  with  three  vertical 
rows  on  a  stem  or  axis. 


Throat,  the  top  of  the  tubular  part 

of  a  gamopetalous  corolla. 
Truncate,     appearing    as     if    cut 

squarely  off,  as  the  leaves  of  the 

tulip-tree. 
Tubercled,     covered    with    warty 

growths. 
Tubercular,    having  tubercles,   or 

like  a  tubercle. 
Two-ranked,    with    three  vertical 

rows  on  a  stem  or  axis. 

Utricle,  a  small  bladdery  ovary- 
wall. 

9f 

Versatile,  turning  freely  on  its  sup- 
port, as  an  anther  on  its  filament. 

Whorled,  arranged  hi  a  circle 
around  an  axis,  as  the  leaves  of 
some  lilies. 

Wings,  the  side-petals  of  a  papilio- 
naceous flower. 


. 


IlffDEX 


Abies,  17. 
Abutilon,  148. 
Acanthacese,  210. 
Acanthus  Family,  210. 
Acer,  141. 
Aceracese,  140,  141. 
Achillea,  281. 
Aconitum,  80. 
Acorus,  25. 
Actsea,  79. 
Adder' s-tongue,  36. 
Adlumia,  92. 
^Esculus,  142. 
Agrostemma,  73. 
Aizoaceae,  69. 
Alder,  55,  139. 
Alfalfa,  124. 
Alisma,  21. 
Alismacese,  21. 
Alleghany  Vine,  92. 
Allium,  34. 
Alnus,  54,  55. 
Aluni  Root,  103. 
Alyssum,  98,  99. 
Amaryllidacese,  42. 
Amaryllis  Family,  42. 
Amelanchier,  110. 
American  Aspen,  47. 
Amianthium,  32,  33. 
Amorpha,  126. 
Ampelopsis,  146. 
Amsonia,  178,  179. 
Anagallis,  174. 
Anarcardiaceae,  137. 


Andromeda,  168. 
Anemone,  80,  81. 
Anemone,  Rue,  82. 
Anemonella,  82. 
Angiosperms,  20. 
Anonaceae,  88. 
Anthemis,  231. 
Antirrhinum,  203. 
Apetalous  Division,  6. 
Apkyllon,  208. 
Apocynacese,  178. 
Apocynum,  179,  180. 
Apple,  109. 
Aquifoliacese,  138. 
Aquilegia,  79. 
Arabis,  98. 
Aracese,  23. 
Aralia,  157,  158. 
Araliaceae,  157. 
Arbor  Vitse,  18. 
Arbutus,  Trailing,  169. 
Arctostaphylos,  169. 
Arissema,  24,  25. 
Aristolochia,  65. 
Aristolochiaceae,  64,  65. 
Arrowhead,  22. 
Arrowwood,  216,  217. 
Arum  Family,  23. 
Asarum,  65. 

Asclepiadacese,  180,  181. 
Asclepias,  181,  182. 
Ash,  134,  175. 
Ash,  Mountain,  109. 
Asimina,  88. 


243 


244 


FOUNDATIONS   OF  BOTANY 


Asparagus,  38. 
Asp,  Quaking,  47. 
Aspen,  American,  47. 
Astragalus,  127,  128. 
Atamasco  Lily,  43. 
Avens,  114,  115. 

Babies'  Toes,  134. 
Bachelor's  Button,  233. 
Bald  Cypress,  18. 
Balsam,  143. 
Balsam  Family,  143. 
Balsam  Fir,  17. 
Balsaminacese,  143. 
Bamboo-vine,  42. 
Baneberry,  79. 
Baptisia,  122. 
Barberry,  84. 
Barberry  Family,  84. 
Barren  Strawberry,  113. 
Basswood,  147. 
Bastard  Toad-flax,  64. 
Bay  berry,  49. 
Bayberry  Family,  49. 
Beaked  Hazelnut,  53. 
Bearberry,  169. 
Bedstraw,  215. 
Beech,  56. 
Beech  Family,  55. 
Beggar's  Lice,  190. 
Begonia,  152,  153,  154. 
Begoniacese,  152. 
Begonia  Family,  152. 
Bell  Flower,  223. 
Bell  Flower  Family,  223. 
Bellis,  228. 
Bellwort,  33. 
Benjamin,  41. 
Berberidacese,  84. 
Berberis,  84,  85. 
Berchemia,  144. 


Betula,  53,  54. 
Betulacese,  61. 
Bignonia,  206. 
Bignoniacese,  206. 
Bignonia  Family,  206. 
Bindweed,  184. 
Birch,  53,  54. 
Birch  Family,  61. 
Bird's  Pepper,  94. 
Bishop's  Cap,  103. 
Bitter  Cress,  97. 
Bittersweet,  139,  199. 
Black  Alder,  139. 
Blackberry,  112. 
Black  Gum,  164. 
Black  Haw,  217. 
Black  Walnut,  50. 
Bladder-nut,  140. 
Bladder-nut  Family,  140. 
Bladderwort,  209,  210. 
Bladderwort  Family,  209. 
Bleeding  Heart,  92. 
Bloodroot,  90. 
Blue  Beech,  52. 
Bluebell,  187. 
Bluebells,  190. 
Blueberry,  170. 
Blue  Cohosh,  85. 
Blue  Dandelion,  234. 
Blue  Devils,  191. 
Blue  Flag,  45. 
Blue  Sailors,  234. 
Blue  Thistle,  191. 
Bluets,  213. 
Blue  Valerian,  187. 
Blueweed,  191. 
Borage  Family,  188. 
Borraginaceae,  188. 
Boston  Ivy,  146. 
Bouvardia,  214. 
Box  Elder,  141. 


INDEX 


245 


Brassica,  95,  96. 
Breeches  Flower,  91. 
Bridal  Wreath,  108. 
Brooklime,  204. 
Broom-rape  Family,  208. 
Broussonetia,  62. 
Brunella,  196. 
Buck-bean,  178. 
Buckeye,  142. 
Buckeye  Family,  142. 
Buckthorn,  144. 
Buckthorn  Family,  143. 
Buckwheat,  67. 
Buckwheat  Family,  66. 
Buffalo  Apple,  128. 
Buffalo  Pea,  128. 
Bull  Nut,  51. 
Bull's-eye,  231. 
Bulrush,  24. 
Bunch-berry,  163. 
Bur,  Buffalo,  200. 
Bur,  Sand,  200. 
Butter  and  Eggs,  203. 
Buttercup,  83. 
Buttercup  Family,  77,  li 
Butternut,  50. 
Butterweed,  232. 
Button  Snakeroot,  159. 
Buttonwood,  105. 

Cactacese,  154. 
Cactus  Family,  154. 
Calamus,  25. 
Calico  Bush,  168. 
Callicarpa,  193. 
Caltha,  78. 
Calycanthacese,  87. 
Calycanthus,  87,  88. 
Calycanthus  Family,  87. 
Calystegia,  183,  184. 
Camassia,  36,  37. 


Campanula,  223. 
Campanulacese,  223. 
Campanula  Family,  223. 
Cancer  Root,  208. 
Cannabis,  62. 
Cantaloupe,  222. 
Caper  Family,  99. 
Capparidacese,  99. 
Caprifoliacese,  215. 
Capsella,  98. 
Caraway,  160. 
Cardamine,  97. 
Carnation,  75. 
Carpenter-weed,  196. 
Carpet-weed,  70. 
Carpinus,  51,  52. 
Carrion  Flower,  41. 
Carrot,  162. 
Carum,  160. 
.    Carya,  50,  51. 

Caryophyllaceae,  71,  72. 
Castanea,  56. 
Castilleia,  205. 
Catalpa,  207. 
Cat-brier,  42. 
Catchfly,  74. 
Catnip,  195. 
Cat-tail,  20. 
Cat-tail  Family,  20. 
Caulophyllum,  86. 
Ceanothus,  144,  145. 
Cedar,  18,  19. 
Celandine,  90. 
Celastraceae,  139. 
Celastrus,  139. 
Celtis,  60. 
Centaurea,  233. 
Cerastium,  72. 
Cercis,  120. 
Cereus,  155. 
Chamselirium,  32. 


246 


FOUNDATIONS   OF   BOTANY 


Charlock,  95,  96. 
Cheeses,  148. 
Chelidonium,  90. 
Chenopodiaceae,  68. 
Chenopodium,  68,  69. 
Cherry,  117. 
Chestnut,  56. 
Chickweed,  72. 
Chickweed  Wintergreen,  173. 
Chicory,  234. 
Chimaphila,  164,  165. 
Chinese  Sacred  Lily,  43. 
Chinquapin,  56. 
Chinquapin,  Water,  76. 
Chionanthus,  176,  177. 
Chocolate  Root,  115. 
Chokeberry,  109. 
Chokecherry,  117. 
Chokepear,  109. 
Chrysanthemum,  231,  232. 
Cichorium,  234. 
Cinquefoil,  114. 
Circsea,  157. 
Cirsium,  233. 
Citrullus,  222. 
Citrus,  133. 
Cladrastis,  121. 
Claytonia,  70. 
Clematis,  82. 
Cleome,  100. 
Clove  Pink,  75. 
Clover,  124,  125. 
Cochlearia,  95. 
Coffee  Tree,  121. 
Cohosh,  85. 
Columbine,  79. 
Comandra,  64. 
Comfrey,  189. 
Commelina,  27. 
Commelinacese,  26. 
Composites,  224-228. 


Composite  Family,  224-228. 
Cone-flower,  230. 
Coniferae,  13. 
Conopholis,  208. 
Convallaria,  40. 
Convolvulacese,  183. 
Convolvulus,  184. 
Convolvulus  Family,  183. 
Coptis,  79. 
Coreopsis,  229,  230. 
Cornaceae,  162, 
Corn  Cockle,  73. 
Cornel,  163. 
Corn  Gromwell,  191. 
Corn  Salad,  221. 
Cornus,  162,  163. 
Corydalis,  93. 
Corylus,  52,  53. 
Cotton  wood,  48. 
Cow  Lily,  77. 
Cow  Parsnip,  162. 
Cowslip,  78. 
Crab  Apple,  109. 
Cranberry,  171. 
Cranberry  Tree,  216. 
Cranesbill,  130. 
Cratsegus,  110,  111. 
Creepers,  183. 
Creeping  Charley,  195. 
Cress,  97. 
Crinkle  Root,  97. 
Crocus,  45. 
Cross-vine,  206. 
Crowfoot,  83. 
Crowfoot  Family,  77,  78. 
Crown  Imperial,  35. 
Crown  of  Thorns,  136. 
Crow's  Foot,  97. 
Crow-victuals,  195. 
Cruciferse,  93,  94. 
Cucumber,  222. 


INDEX 


247 


Cucumis,  222. 
Cucurbita,  222. 
Cucurbitacese,  221. 
Currant,  104. 
Cuscuta,  183. 
Cydouia,  108. 
Cynoglossum,  189. 
Cyperaceae,  23. 
Cypress,  18,  137. 
Cypress  Vine,  184. 
Cypripediura,  46. 
Cytisus,  123. 

Daffodil,  43. 
Daffy,  43. 
Daisy,  228,  231. 
Dakota  Turnip,  126. 
Dandelion,  236. 
Datura,  200,  201. 
Daucus,  162. 
Dayflower,  Virginia,  27. 
Day-lily,  34. 
Dead  Nettle,  196. 
Deerberry,  171. 
Delphinium,  80. 
Dentaria,  97. 
Deptford  Pink,  75. 
Desmanthus,  119,  120. 
Deutzia,  104. 
Devil's  Bit,  32. 
Dewberry,  112. 
Dianthera,  211. 
Dianthus,  75. 
Dicentra,  91,  92. 
Dicotyledonous  Plants,  47. 
Diervilla,  219,  220. 
Diospyros,  174. 
Dock,  66,  67. 
Dodecatheon,  171,  172. 
Dogbane,  180. 
Dogbane  Family,  178. 


Dogberry,  109. 
Dog-brier,  42. 
Dog-bur,  189. 
Dog-fennel,  231. 
Dog's-tooth  Violet,  36. 
Dogwood,  163. 
Dogwood  Family,  162. 
Dogwood,  Poison,  138. 
Dragon  Eoot,  25. 
Dutchman's  Breeches,  91. 
Dutchman's  Pipe,  65. 
Dutchman's  Pipe  Family,  64,  65. 

Ear  Drops,  92. 
Easter-flower,  43. 
Ebenacese,  174. 
Ebony  Family,  174. 
Echinocystis,  222. 
Echinospermum,  189,  190. 
Echium,  191. 
Elder,  215,  216. 
Elder,  Wild,  157. 
Elm,  60. 
Elm  Family,  59. 
Enchanter's  Nightshade,  157. 
English  Ivy,  157. 
English  Walnut,  50. 
Epigaea,  169. 
Ericaceae,  166,  167. 
Erigenia,  159,  160. 
Erigeron,  228,  229. 
Eryngium,  158,  159. 
Erythronium,  36. 
Eschscholtzia,  90. 
Euonymus,  139,  140. 
Euphorbia,  136,  137. 
Euphorbiaceae,  135. 
Eutoca,  188. 

Evening  Primrose  Family,  156. 
Eyebright,  213. 


248 


FOUNDATIONS   OF  BOTANY 


Fagacese,  55. 
Fagus,  55,  56. 
Fairycup,  103. 
False  Buckwheat,  67. 
False  Dandelion,  236. 
False  Indigo,  126. 
False  Mitre-wort,  102. 
False  Spikenard,  38. 
Farkleberry,  171. 
Feverwort,  218. 
Field  Garlic,  34. 
Figwort  Family,  201,  202. 
Fir,  17. 
Fire  Pink,  74. 
Flag,  45,  46. 
Flax,  133. 
Flax  Family,  132. 
Fleabane,  229. 
Fleur-de-lis,  45,  46. 
Flowering  Maple,  148. 
Flowering  Moss,  186. 
Fly  Poison,  33. 
Forget-me-not,  190,  191. 
Forsytkia,  176. 
Fragaria,  113. 
Fraxinus,  175. 
French  Mulberry,  193. 
Fringe  Cap,  103. 
Fringe  Tree,  177. 
Fritillaria,  35. 
Fuchsia,  156. 

Galium,  214,  215. 
Garden  Columbine,  79. 
Garden  Sage,  198. 
Garget  Root,  69. 
Garlic,  34. 

Gaylussacia,  169,  170. 
Gentianacese,  177. 
Gentian  Family,  177. 
Geraniacese,  129,  130. 


Geranium,  130,  131. 
Geranium  Family,  129,  130. 
Geum,  114,  115. 
Gill-over-the-ground,  195. 
Gillyflower,  99. 
Ginseng  Family,  157. 
Gleditschia,  121. 
Golden  Alexanders,  161. 
Golden  Chain,  123. 
Gold  Thread,  79. 
Gooseberry,  104. 
Goosefoot,  69. 
Goosefoot  Family,  68. 
Goose  Grass,  214. 
Gourd  Family,  221. 
Graminese,  23. 
Grape,  145,  146. 
Grape  Family,  145. 
Grass  Family,  23. 
Grass  Pink,  75. 
Gratiola,  204. 
Graveyard  Moss,  137. 
Green-brier,  42. 
Green  Dragon,  25. 
Gromwell,  Corn,  191. 
Ground  Ivy,  195. 
Ground  Pink,  186. 
Ground  Plum,  128. 
Guinea-hen  Flower,  35. 
Gum,  Black,  164. 
Gymnocladus,  120,  121. 
Gymnosperms,  13. 
Gypsy  Weed,  205. 

Hackberry,  60. 
Hackmatack,  18. 
Harbinger  of  Spring,  160. 
Hardback,  108. 
Harebell,  223. 
Haw,  110,  ,111,  217. 
Hazelnut,  52,  53. 


INDEX 


249 


Heal-all,  196. 
Heart's-ease,  151. 
Heath  Family,  166,  167. 
Hedge  Mustard,  95. 
Helenium,  230. 
Heliotrope,  189. 
Heliotropium,  189. 
Hellebore,  White,  32. 
Hemerocallis,  33,  34. 
Hemlock,  17. 
Hemp,  62, 
Hen-bit,  196. 
Hepatica,  81. 
Heracleum,  161,  162. 
Herb  Robert,  130. 
Heuchera,  103. 
Hickory,  51. 
Hieracium,  235. 
High-bush  Cranberry,  216. 
Hippocastanacese,  142. 
Hobble-bush,  216. 
Holly,  138,  139. 
Holly  Family,  138. 
Honey  Locust,.  121. 
Honeysuckle,  167,  218-220. 
Honeysuckle  Family,  215. 
Hop  Clover,  125. 
Hop-tree,  134. 
Horehound,  195. 
Hornbeam,  52. 
Horse-brier,  42. 
Horse-chestnut,  142. 
Horse-gentian,  218. 
Horse  Nettle,  199. 
Horse-radish,  95. 
Hound's-tongue,  189. 
Houstonia,  213. 
Hoy  a,  183. 

Huckleberry,  170,  171. 
Hyacinth,  37. 
Hyacinthus,  37. 


Hydrophyllacese,  187. 
Hydrophyllum,  187,  188. 
Hypericacese,  148. 
Hypericum,  149. 
Hypoxis,  43. 

Ice  Plant,  69. 
Ice-plant  Family,  69. 
Ilex,  138,  139. 
Impatiens,  143. 
Indian  Chief,  172. 
Indian  Cress  Family,  132. 
Indian  Hemp,  180. 
Indian  Paint,  191. 
Indian  Pink,  205. 
Indian  Pipe,  166. 
Indian  Poke,  32. 
Indian  Turnip,  25. 
Indigo,  122. 
Indigo,  False,  126. 
Innocence,  213. 
Ipomoea,  184,  185. 
Iridacese,  45. 
Iris,  45,  46. 
Iris  Family,  45. 
Irish  Potato,  200. 
Iron  Wood,  52. 
Isopyrum,  78. 
Ivy,  138. 

Jack-in-the-pulpit,  25. 
Jacob's  Ladder,  39,  187,  203. 
Japanese  Ivy,  146. 
Jatropha,  137. 
Jerusalem  Oak,  69. 
Jewel  Weed,  143. 
Jimson  Weed,  201. 
Johnny-jump-up,  151. 
Jointed  Charlock,  96. 
Juglandacese,  49,  50. 
Juglans,  50. 


250 


FOUNDATIONS   OF  BOTANY 


Juncacese,  29. 
Juneberry,  110. 
Juniper,  19. 
Juniperus,  19. 

Kalmia,  168. 
Kicking  Colt,  143. 
King  Nut,  51. 
Kinnikinnik,  163. 
Knawel,  73. 
Knot-grass,  67. 
Krigia,  234. 

Labiatse,  193,  194. 
Laburnum,  123. 
Lactuca,  236,  237. 
Ladies'  Eardrop,  156. 
Lady's-delight,  151. 
Lady's-slipper,  46,  143. 
Lady's  Tresses,  46. 
Lagenaria,  222. 
Lamb  Lettuce,  221. 
Lamium,  196. 
Larch,  18. 
Larix,  17,  18. 
Larkspur,  80. 
Lathyrus,  129. 
Lauracese,  88,  89. 
Laurel,  168,  169. 
Laurel  Family,  88,  89. 
Leather  Flower,  82. 
LeguminossB,  117-119. 
Lemon,  133. 
Lentibulariacese,  209. 
Leontodon,  235. 
Leonurus,  196,  197. 
Lepidium,  94. 
Lettuce,  237. 
Lever-wood,  52. 
Liguliflorse,  234. 
Ligustrum,  177. 


Lilac,  176. 
Liliacese,  29. 
Lilium,  35. 
Lily,  34,  35. 
Lily  Family,  29. 
Lily-of-the-valley,  40. 
Lime,  133. 
Linacese,  132. 
Linaria,  202,  203. 
Linden,  147. 

Linden  Family,  146,  147. 
Lindera,  89. 
Linnsea,  217,  218. 
Linum,  132,  133. 
Liriodendron,  87. 
Lithospermum,  191. 
Live  Oak,  58. 
Liver-berry,  39. 
Liverleaf,  81. 
Liverwort,  81. 
Lobularia,  98,  99. 
Locust,  121,  127. 
London  Pride,  74. 
Lonicera,  218,  219. 
Loosestrife,  173. 
Loranthacese,  63. 
Lotus,  76. 
Lousewort,  206. 
Lungwort,  190. 
Lupinus,  123. 
Lychnis,  74. 
Lycium,  199. 
Lycopersicum,  200. 
Lysimachia,  173. 

Madura,  61,  62. 
Madder  Family,  212,  213. 
Magnolia,  86. 
Magnoliacese,  85,  86. 
Magnolia  Family,  85,  86. 
Maianthemum,  39. 


INDEX 


251 


Mallow,  148. 
Mallow  Family,  147,  148. 
Malva,  148. 
Malvaceee,  147,  148. 
Maple,  141. 

Maple  Family,  140,  141. 
Marguerite,  232. 
Marigold,  Marsh,  78. 
Marrubium,  195. 
Marsh  Bell-flower,  223. 
Marsh  Marigold,  78. 
Marsh  Trefoil,  178. 
Matrimony  Vine,  199. 
Matthiola,  99. 
May-apple,  85. 
Mayflower,  102,  169. 
Mayweed,  231. 
May  Wings,  134. 
Meadow  Buttercup,  78. 
Meadow  Garlic,  34, 
Meadow  Lily,  35. 
Meadow  Parsnip,  161. 
Meadow  Rue,  84. 
Medicago,  124. 
Medick,  124. 
Melilotus,  124. 
Melon,  221. 
Menyanthes,  178. 
Mercury,  138. 
Mertensia,  190. 
Mignonette,  100. 
Mignonette  Family,  100. 
Milkweed,  181,  182. 
Milkweed  Family,  180,  18 
Mint  Family,  193,  194. 
Mistletoe,  64. 
Mistletoe  Family,  63. 
Mitchella,  214. 
Mitella,  102. 
Mitre-wort,  102. 
Mollugo,  70. 


Monkshood,  80. 
Monocotyledonous  Plants,  20. 
Monotropa,  166. 
Moracese,  61. 
Morning-glory,  184,  185. 
Morning-glory  Family,  183. 
Morus,  61. 
Moss  Pink,  186. 
Motherwort,  197. 
Mountain  Ash,  109. 
Mountain  Fringe,  92. 
Mouse-ear  Chickweed,  72. 
Mulberry,  61,  62,  111. 
Mulberry  Family,  61. 
Mulberry,  French,  193. 
Mulberry,  Mexican,  193. 
Mullein,  Moth,  202. 
Mullein  Pink,  74. 
Muskmelon,  222. 
Mustard,  95,  96. 
Mustard  Family,  93,  94. 
Myosotis,  190,  191. 
Myrica,  49. 
Myricacese,  49. 

Narcissus,  43. 
Nasturtium,  96,  132. 
Nelumbo,  76. 
Nepeta,  195. 
Nerium,  180. 
Nettle,  63. 

Nettle  Family,  62,  63. 
New  Jersey  Tea,  145. 
Nightshade,  199. 
Nightshade  Family,  198. 
Ninebark,  107. 
Noble  Liverwort,  81. 
None-so-pretty,  74. 
Nonesuch,  124. 
Nuphar,  76,  77. 
Nutmeg  Melon,  222. 


252 


FOUNDATIONS   OF   BOTANY 


Nymphaea,  76. 
Nymphseaceae,  75. 
Nyssa,  164. 

Oak,  57,  58,  59. 
Oakesia,  33. 
Obolaria,  177,  178. 
(Enothera,  156. 
(Enotheracese,  156. 
Oleacese,  175. 
Oleander,  180. 
Olive  Family,  176. 
Onion,  34. 
Opuntia,  154,  155. 
Orange,  133. 
Orange  Grass,  149. 
Orange,  Osage,  62. 
Orchidaceae,  46. 
Orchis  Family,  46. 
Ornithogalum,  37. 
Orobanchaceae,  208. 
Osage  Orange,  62. 
Osmorrhiza,  160. 
Ostrya,  52. 
Oxalidaceae,  131. 
Oxalis,  131. 

Paeonia,  78. 
Paeony,  78. 
Paint-brush,  205. 
Painted  Cup,  205. 
Pansy,  151. 
Papaver,  91. 
Papaveraceae,  89,  90. 
Paper  Mulberry,  62. 
Pappoose  Root,  85. 
Parsley  Family,  158. 
Parsnip,  161. 
Partridge  Berry,  214. 
Pasque  Flower,  80. 
Passiflora,  151,  152. 


Passifloraceae,  151. 
Passion-flower,  151,  152. 
Passion-flower  Family,  151. 
Pastinaca,  161. 
Pawpaw,  88. 
Pawpaw  Family,  88. 
Pea,  129. 

Pea  Family,  117-119. 
Peach,  116. 
Pear,  108. 
Pecan,  50. 
Pedicularis,  206. 
Pelargonium,  130,  131. 
Pennywort,  178. 
Pentstemon,  203,  204. 
Peony,  78. 

Pepper-and-salt,  160. 
Peppergrass,  94. 
Pepper  Root,  97. 
Periwinkle,  179. 
Persimmon,  174. 
Petunia,  201. 
Phacelia,  188. 
Philadelphus,  103. 
Phlox,  185,  186. 
Phlox  Family,  185. 
Phoradendron,  63,  64. 
Phyllocactus,  155. 
Physocarpus,  107. 
Phytolacca,  69. 
Phytolaccaceae,  69. 
Picea,  16. 

Pickerel  Weed,  28,  29. 
Pickerel-weed  Family,  28. 
Pignut,  51. 
Pimpernel,  174. 
Pine,  14,  15,  16. 
Pine  Family,  13. 
Pine-sap,  166. 
Pine-weed,  149. 
Pink,  74,  75,  167. 


INDEX 


253 


Pink  Family,  71,  72. 

Pinus,  14. 

Pipe  Vine,  65. 

Pipsissewa,  165. 

Pisum,  129. 

Pitcher-plant  Family,  101. 

Plantaginacese,  211. 

Plantago,  211,  212. 

Plantain,  211,  212. 

Plantain  Family,  211. 

Plantain,  Water,  21. 

Platanacese,  105. 

Platanus,  105. 

Plum,  116. 

Podophyllum,  85.     • 

Poet's  Narcissus,  43. 

Poison  Ivy,  138. 

Poison  Vine,  138. 

Pokeberry,  69. 

Pokeberry  Family,  69. 

Poke,  Indian,  32. 

Poke  weed,  69. 

Pokeweed  Family,  69. 

Polanisia,  99. 

Polemoniacese,  185. 

Polemonium,  186,  187. 

Polygala,  134,  135. 

Polygalacese,  134. 

Polygala  Family,  134. 

Polygonacese,  66. 

Polygonatum,  39,  40. 

Polygonum,  67.        • 

Pomme  Blanche,  126. 

Pontederia,  28. 

Pontederiacese,  28. 

Poor  Man's  Weather-glass,  174. 

Poplar,  47. 

Poplar,  White,  87. 

Poppy,  91. 

Poppy  Family,  89,  90. 

Populus,  47,  48. 


Portulaca,  71. 
Portulacacese,  70. 
Portulaca  Family,  70. 
Potato,  200. 
Potentilla,  114. 
Prairie  Apple,  128. 
Prairie  Fire,  205. 
Prickly  Ash,  133. 
Prickly  Pear,  154. 
Primrose,  172. 
Primrose  Family,  171. 
Primula,  172. 
Primulacese,  171. 
Prince's  Pine,  165. 
Privet,  177. 
Primus,  116,  117. 
Psoralea,  126. 
Ptelea,  134. 
Puccoon,  191. 
Pudding-berry,  163. 
Pulse  Family,  117-119. 
Purslane,  71. 
Purslane  Family,  70. 
Pyrola,  165. 
Pyrolacese,  164. 
Pyrola  Family,  164. 
Pyrrhopappus,  236. 
Pyrus,  108,  109. 

Quaker  Ladies,  213. 
Quaking  Asp,  47. 
Quamoclit,  184. 
Quercus,  56-59. 
Quince,  108. 

Radish,  Wild,  96. 
Ragweed,  232. 
Ranunculaceae,  77,  78. 
Ranunculus,  82,  83. 
Raphanus,  96. 
Raspberry,  111,  112. 


254 


FOUNDATIONS   OF  BOTANY 


Rattan-vine,  144. 

Rattlebox,  74. 

Rattlesnake  Master,  159. 

Rattlesnake  Weed,  235. 

Redbud,  120. 

Red  Cedar,  19. 

Red  Root,  145. 

Reseda,  100. 

Resedaceae,  100. 

Rhamnaceae,  143. 

Rhamnus,  144. 

Rhododendron,  167. 

Rhus,  137,  138. 

Ribes,  104. 

Ribgrass,  212. 

Robinia,  127. 

Robin-runaway,  195. 

Robin's  Plantain,  229. 

Rocky  Mountain  Bee  Plant,  100. 

Rosa,  115,  116. 

Rosacese,  105-107. 

Rose,  115. 

Rose  Family,  105-107. 

Rosemary,  168. 

Rowan  Tree,  109. 

Rubiaceae,  212,  213. 

Rubus,  111-113. 

Rudbeckia,  230. 

Rue  Anemone,  82. 

Rue  Family,  133. 

Ruellia,  210. 

Rumex,  66,  67. 

Rush  Family,  29. 

Rutaceae,  133. 

Rutland  Beauty,  183. 

Sage,  198. 
Sagittaria,  21,  22. 
Salicacese,  47. 
Salix,  48. 
Salsify, 


Salvia,  197,  198. 
Sambucus,  215,  216. 
Sandalwood  Family,  64. 
Sand  Bur,  200. 
Sanguinaria,  90. 
Sanicle,  159. 
Sanicula,  159. 
Santalacese,  64. 
Sarracenia,  101. 
Sarraceniaceae,  101. 
Sarsaparilla,  157,  158. 
Sassafras,  89. 
Savin,  19. 
Saxifraga,  102. 
Saxifragaceae,  101. 
Saxifrage,  102. 
Saxifrage  Family,  101. 
Schrankia,  120. 
Scilla,  36. 
Scleranthus,  73. 
Scrophulariaceae,  201,  202. 
Scutellaria,  194,  195. 
Sedge  Family,  23. 
Self-heal,  196. 
Senecio,  232. 
Sensitive  Brier,  120. 
Sensitive  Rose,  120. 
Service  Berry,  110. 
Shad  Bush,  110. 
Shame  Vine,  120. 
Sheep-lice,  189. 
Sheep  Sorrel,  66. 
Shellbark,  51. 
Shepherd's  Purse,  98. 
Sheriff  Pink,  231. 
Shin-leaf,  165. 
Shooting  Star,  172. 
Shrub,  88. 
Sickle  Pod,  98. 
Sicyos,  222. 
Side-saddle  Flower,  101. 


INDEX 


255 


Silene,  73,  74. 
Sisymbrium,  95. 
Sisyrinchium,  46. 
Skullcap,  194,  195. 
Skunk  Cabbage,  25. 
Smilacese,  31. 
Smilacina,  38. 
Srnilax,  41,  42. 
Suakeroot,  135. 
Snakeroot,  Black,  159. 
Snakeroot,  Samson's,  126. 
Snapdragon,  203. 
Snappers,  74. 
Snapweed,  143. 
Sneezeweed,  230. 
Snowball,  216. 
Snowberry,  217. 
Solanacese,  198. 
Solanum,  199,  200. 
Solomon's  Seal,  39,  40. 
Sonchus,  237. 
Sorrel,  Sheep,  66. 
Spanish  Dagger,  38. 
Spatter-dock,  77. 
Spearwort,  83. 
Specularia,  223,  224. 
Speedwell,  205. 
Spice  Bush,  88,  89. 
Spiderwort,  27. 
Spiderwort  Family,  26. 
Spikenard,  False,  38. 
Spinach,  68. 
Spinacia,  68. 
Spiranthes,  46. 
Spirea,  107,  108. 
Spring  Beauty,  70,  81. 
Spruce,  16,  17. 
Spurge,  136,  137. 
Spurge  Family,  135. 
Spurge  Nettle,  137. 
Squash,  222. 


Squawroot,  41,  208. 
Squaw  Vine,  214. 
Squill,  36. 
Squirrel  Corn,  92. 
Stachys,  197. 
Staff-tree  Family,  139. 
Stagger-bush,  168. 
Staphylea,  140. 
Staphyleacese,  140. 
Star-flower,  173. 
Star-grass,  43. 
Star  of  Bethlehem,  37. 
Steironema,  173. 
Stellaria,  72. 
Stick-tights,  189. 
Stitchwort,  72. 
St.  Johnswort,  149. 
St.  Johnswort  Family,  148. 
Stock,  99. 
Strawberry,  113. 
Strawberry  Bush,  88,  140. 
Straw  Lilies,  33. 
Streptopus,  39. 
Sugar  Pear,  110. 
Sugar  Plum,  110. 
Sumach,  137,  138. 
Sumach  Family,  137. 
Sun  drops,  156. 
Supple  Jack,  144. 
Sweet  Alyssum,  99. 
Sweet  Bay,  86. 
Sweetbrier,  116. 
Sweet  Cicely,  160. 
Sweet  Clover,  124. 
Sweet  Fern,  49. 
Sweet  Flag,  25. 
Sweet  Potato,  184. 
Sweet-scented  Shrub,  88. 
Sweet  William,  75. 
Sycamore,  105. 
Sycamore  Family,  105. 


256 


FOUNDATIONS   OF   BOTANY 


Symphoricarpus,  217. 
Symplocarpus,  25. 
Syringa,  103,  176. 

Tamarack,  18. 
Tangleberry,  170. 
Tansy  Mustard,  95. 
Taraxacum,  235,  236. 
Tassel  Tree,  148. 
Taxodium,  18. 
Tecoma,  207. 
Thalictrum,  84. 
Thaspium,  161. 
Thistle,  233,  237. 
Thorn,  110. 
Thuya,  18,  19. 
Thyme,  198. 
Thymus,  198. 
Tiarella,  102. 
Tickseed,  229,  230. 
Tilia,  147. 
Tiliacese,  146,  147. 
Tinker-weed,  218. 
Tipsin,  126. 
Toad-flax,  64. 
Toad-flax,  Wild,  203. 
Tomato,  200. 
Tongue-grass,  94. 
Toothache-tree,  133. 
Toothwort,  97. 
Tradescantia,  27. 
Trailing  Arbutus,  169. 
Trefoil,  Marsh,  178. 
Trientalis,  172,  173. 
Trifolium,  125. 
Trillium,  40,  41. 
Triosteum,  218. 
Tropaeolacese,  132. 
Tropseolum,  132. 
Tropseoluin  Family,  132. 
Trumpet  Creeper,  207. 


Trumpet  Flower,  207. 
Tsuga,  17. 

Tubuliflorae,  227,  228. 
Tulip,  36. 
Tulipa,  36. 
Tulip  Tree,  87. 
Tupelo,  164. 
Turkey  Pea,  160. 
Twin-flower,  218. 
Two-eye  Berry,  214. 
Typha,  20. 
Typhacese,  20. 

Ulmaceae,  59. 
Ulinus,  59,  60. 
Umbelliferse,  158. 
Umbrella  Tree,  86. 
Unicorn-root,  32. 
Urtica,  63. 
Urticaceae,  62,  63. 
Utricularia,  209,  210. 
Uvularia,  33. 

Vaccinium,  170,  171. 
Valerian,  220. 
Valeriana,  220. 
Valerianacese,  220. 
Valerianella,  221. 
Valerian  Family,  220. 
Veratrum,  32. 
Verbascum,  202. 
Verbena,  192,  193. 
Verbenacese,  192. 
Verbena  Family,  192. 
Veronica,  204,  205. 
Vervain,  192. 
Vetch,  128,  129. 
Viburnum,  216,  217. 
Vicia,  128. 
Vinca,  179. 
Vine  Family,  145. 


INDEX 


257 


Viola,  149,  150,  151. 
Violaceee,  149. 
Violet,  150,  151. 
Violet  Family,  149. 
Virginia  Creeper,  146. 
Virginia  Dayflower,  27. 
Vitacese,'  145. 
Vitis,  145,  146. 

Wafer  Ash,  134. 
Wahoo,  140. 
Wait-a-bit,  42. 
Wake-robin,  40,  41. 
Waldsteinia,  113. 
Walnut,  50. 

Walnut  Family,  49,  50. 
Wandering  Jew,  28. 
Water  Chinquapin,  76. 
Watercress,  96. 
Waterleaf  Family,  187. 
Water-lily,  76. 
Water-lily  Family,  75. 
Water  Plantain,  21. 
Water-plantain  Family,  21. 
Water  Willow,  211. 
Waxberry,  49. 
Wax  Plant,  183. 
Wax-work,  139. 
Weigela,  220. 
White  Hellebore,  32. 
White  Poplar,  87. 
White  Water-lily,  76. 
Whiteweed,  231. 
Whitewood,  87,  147. 
Whitlavia,  188. 
Wickakee,  205. 


Wild  Coffee,  218. 

Wild  Flax,  203. 

Wild  Ginger,  65. 

Wild  Hyacinth,  37,  92. 

Wild  Licorice,  215. 

Wild  Lily-of-the-valley,  39. 

Wild  Oats,  33. 

Wild  Pear,  110. 

Wild  Pink,  74. 

Wild  Potato  Vine,  185. 

Wild  Raddish,  96. 

Wild  Sweet  William,  186. 

Willow,  48. 

Willow  Family,  47. 

Wind-flower,  81. 

Winterberry,  139. 

Wintergreen,  165,  173. 

Wistaria,  127. 

Witch-hobble,  216. 

Withe-rod,  217. 

Woodbine,  146. 

Wood-sorrel,  131. 

Wood-sorrel  Family,  131. 

Yarrow,  231. 
Yellow  Flag,  46. 
Yellow  Pond  Lily,  77. 
Yellow  Sweet  Clover,  124. 
Yellowwood,  121. 
Yucca,  37,  38. 

Xanthoxyluin,  133. 

Zebrina,  28. 
Zephyranthes,  42,  43. 
Zizia,  161. 


BIOUOGY  LIBRARY 

SEP  14  1932 

MAR    2  1935 

J  ft  1935 


MAR  1  5  1941 
MAR  2  9  1949 


LD  21- 


U.C.  BERKELEY  LIBRARIES 


BIOLOGY 
UBRAtt 

'3 

UNIVERSITY  OF  CALIFORNIA  LIBRARY 


